Claude Code Beginners' Guide: Best Practices

Introduction to Your New AI Pair Programmer

Welcome to the future of software development. Artificial intelligence is no longer just a concept from science fiction; it's a practical, powerful tool that can augment and accelerate our daily coding workflows. At the forefront of this revolution is Anthropic's Claude, a family of sophisticated AI models designed to be helpful, harmless, and honest. When applied to coding, Claude becomes an incredibly capable pair programmer, a tireless assistant, and a knowledgeable guide.

This guide is designed for developers who are ready to move beyond simple "code completion" and embrace a more collaborative, agentic approach to AI-assisted development. We'll explore the best practices for instructing Claude, managing its memory for complex tasks, and wielding the full power of the claude-code command-line tool.

Whether you're looking to onboard to a new codebase faster, automate tedious refactoring, or brainstorm complex architectural solutions, the principles and workflows in this guide will help you transform Claude from a simple chatbot into an indispensable member of your development team. We will synthesize insights from Anthropic's official documentation and engineering blogs to provide a comprehensive, actionable tutorial.

Let's begin.

Part 1: The Foundations: Core Principles for Coding with Claude

Before diving into specific tools and workflows, it's crucial to understand the fundamental principles of communicating with a large language model like Claude. The quality of your output is directly proportional to the quality of your input. Think of it less like a search query and more like giving instructions to a very intelligent, very literal, but non-mind-reading junior developer.

Be Explicit and Direct

This is the golden rule. Vague instructions lead to vague results. Claude 4 models, in particular, are trained to follow instructions with high precision. Don't assume the model knows what you want; tell it exactly.

Less effective:

"Write a function to handle user uploads."

More effective:

"Write a Python function using Flask that handles multipart/form-data image uploads. The function should:
1. Accept files up to 5MB.
2. Only allow .png and .jpg extensions.
3. Save the file to a '/uploads' directory with a UUID as its filename.
4. Return a JSON response with the new file URL on success, or an error message on failure."

If you want Claude to go "above and beyond," you need to ask for it. Phrases like "Include as many relevant features and interactions as possible," or "Go beyond the basics to create a fully-featured implementation" can encourage more comprehensive results.

Provide Context and Motivation

Explaining why you're asking for something helps Claude understand the goal and deliver better-suited responses. Context turns a simple instruction into a problem to be solved.

Less effective:

"NEVER use ellipses in the output."

More effective:

"The output of this function will be read aloud by a text-to-speech engine for accessibility purposes. Therefore, you must NEVER use ellipses (...) because the engine cannot pronounce them correctly. Please write out full sentences."

This explanation allows Claude to generalize. It now understands the constraint is related to speech synthesis and will be more likely to avoid other characters or formatting that would cause similar issues.

Use High-Quality Examples (Few-Shot Prompting)

One of the most powerful techniques is to provide examples of the desired input and output format. This is known as few-shot prompting. Claude is excellent at pattern recognition and will adapt its response to match the style of your examples.

Human: Translate the following Python dictionary to a Java HashMap.

Python:
{'user_id': 123, 'username': 'claude', 'is_active': True}

Java:

Assistant:
import java.util.HashMap;

HashMap<String, Object> user = new HashMap<>();
user.put("user_id", 123);
user.put("username", "claude");
user.put("is_active", true);

When providing examples, be vigilant. Ensure your examples perfectly match the behavior you want to encourage and contain none of the behaviors you want to avoid.

Give Claude a Role (System Prompts)

Assigning a persona or role to Claude at the beginning of a conversation sets the stage for all subsequent interactions. This is typically done using a "system prompt."

Example:

"You are an expert in cybersecurity and secure coding practices. When you review or write code, your primary focus is on identifying and mitigating potential security vulnerabilities, such as SQL injection, XSS, and buffer overflows. All your responses should be from this perspective."

This initial instruction frames the entire conversation, ensuring Claude's responses are consistently filtered through the lens of a security expert.

Use XML Tags for Structure and Clarity

XML tags are a fantastic way to demarcate different parts of your prompt, making it easier for Claude to understand the structure of your request. You can use them to separate instructions, context, examples, and the final query.

Example:

<instructions>
You are an expert Go developer. Your task is to refactor the provided Go code to improve its performance and readability. Please adhere to idiomatic Go practices.
</instructions>

<go_code_to_refactor>
// ... provided Go code ...
</go_code_to_refactor>

<output_format>
Please provide the refactored code inside a single Go code block. Following the code block, add a section in <explanation> tags detailing the specific changes you made and why they improve the code.
</output_format>

This structured approach leaves no room for ambiguity and helps guide Claude to produce a perfectly formatted response.

Part 2: Managing Context and Memory

A single prompt is powerful, but real-world development involves tasks that span multiple files, require historical knowledge, and evolve over time. This is where managing Claude's "memory"—its context window—becomes critical.

The claude-code CLI Memory System: CLAUDE.md

The claude-code command-line tool has a brilliant, file-based memory system built around a special file: CLAUDE.md. Claude automatically reads the contents of this file and includes it in its context at the start of every session in that directory. This provides a persistent, project-specific memory.

There are three main places you can put these memory files:

1. Project Memory (./CLAUDE.md): Located in the root of your project. This is the most common location. You should check this file into Git so that project-specific instructions, commands, and style guides are shared with your entire team.
2. User Memory (~/.claude/CLAUDE.md): Located in your home directory. The contents of this file are loaded for all your projects. This is perfect for personal preferences, like your preferred coding style or custom tool shortcuts that you use everywhere.
3. Parent/Child Directory Memory: Claude recursively looks for CLAUDE.md files. If you're in a subdirectory of a monorepo, it will load the CLAUDE.md from the root and the CLAUDE.md from your current directory. It will also load memory from child directories on-demand as you start interacting with files within them.

Best Practices for CLAUDE.md

Think of your CLAUDE.md file as a carefully crafted prompt that you are constantly refining.

• Be Concise and Structured: Use Markdown headings and bullet points to keep the file readable and organized.
• Document Common Commands: List frequently used build, test, and lint commands. npm run build: Build the project.
• Specify Core Files: Point Claude to key architectural files. Core logic is in src/services/main_service.py.
• Define Code Style: Explicitly state coding conventions. Use ES modules (import/export), not CommonJS (require).
• Explain Project Workflows: Detail processes like Git branching or testing strategies. Always create feature branches from develop.
• Use Imports for Modularity: You can import other files directly into your CLAUDE.md using the @ syntax (e.g., @docs/api_conventions.md). This keeps your main memory file clean and allows for modular context.

You can bootstrap this file by running /init in the claude-code CLI, and you can quickly add new memories during a session by starting your prompt with the # symbol. For more extensive edits, simply use the /memory command to open the file in your default editor.

Techniques for Long Context Recall

Even with CLAUDE.md, complex tasks can fill the context window. Research from Anthropic has shown two powerful techniques to improve Claude's ability to recall specific information from long documents or conversations:

Ask for Reference Quotes: Before answering a question about a large context, instruct Claude to first find and extract the most relevant quotes or snippets from the provided text that support its answer. This forces the model to ground its response in the source material. You can even use a <scratchpad> XML tag for this.

<instructions>
Answer the user's question based on the provided document. Before you write the final answer, use a <scratchpad> to write down the exact quotes from the document that are most relevant to the question.
</instructions>

Provide In-Context Examples: Just as with short prompts, providing a few examples of correctly answered questions about other parts of the document dramatically improves performance. This primes the model for the Q&A task format.

Finally, don't forget the /clear command in the claude-code CLI. If you're switching between unrelated tasks in a long session, use /clear to reset the context window and give Claude a fresh start, preventing confusion from irrelevant past conversations.

Part 3: The Power User's Toolkit: A Deep Dive into the claude-code CLI

While the principles above apply to any interaction with Claude, the claude-code command-line interface unlocks a new level of power and integration. It's an agentic coding assistant that lives in your terminal, understands your codebase, and can take real action.

Installation and Setup

Getting started is straightforward.

System Requirements:

• OS: macOS 10.15+, Ubuntu 20.04+, or Windows via WSL.
• Software: Node.js 18+ is essential.
• Network: An internet connection is required.

Installation:
Open your terminal and run:

npm install -g @anthropic-ai/claude-code

Important: Do not use sudo with this command, as it can cause permission issues. If you encounter errors, consult the official documentation for configuring npm permissions.

Authentication:
The first time you run claude, it will guide you through an authentication process. You can connect via your Anthropic Console account, a Claude Pro subscription, or enterprise platforms like Amazon Bedrock and Google Vertex AI.

Customization and Configuration

Claude Code is designed to be customized to your liking.

• Terminal Optimization: You can match Claude's theme to your terminal's theme using the /config command. You can also configure keyboard shortcuts for line breaks (like Option+Enter) to make multi-line prompts easier.
• Permissions and Allowlisting: By default, Claude Code prioritizes safety and will ask for permission before modifying files or running potentially destructive commands. You can customize this using the /permissions command. For example, you can always allow file edits with /permissions add Edit or allow git commits with /permissions add "Bash(git commit:*)". These settings are stored in .claude/settings.json, which you can share with your team.
• Extending Claude's Abilities:
• Custom Slash Commands: Create your own reusable prompt templates by adding Markdown files to the .claude/commands/ directory. These become available as slash commands. For example, creating refactor.md allows you to run /project:refactor with your predefined refactoring instructions. Use the $ARGUMENTS keyword to pass parameters.
• External Tools with MCP: The Multi-Claude Protocol (MCP) allows Claude to connect to other tools and services. You can set up MCP servers to give Claude capabilities like controlling a web browser (with Puppeteer), querying a database, or interacting with a Sentry instance.

Part 4: Practical Workflows in Action

Theory is valuable, but the real power of Claude Code emerges when you apply it to practical, day-to-day development tasks. Here are several battle-tested workflows used by engineers at Anthropic and beyond.

Workflow 1: Codebase Q&A (Onboarding)

When joining a new project, understanding the codebase is the first hurdle. Use Claude as your personal tour guide. Ask it questions as you would a senior developer.

• "How does logging work in this repository?"
• "Walk me through the steps to create a new API endpoint."
• "What does this async move { ... } block on line 134 of foo.rs do?"
• "What edge cases does the CustomerOnboardingFlowImpl class handle?"

No special prompting is required. Just ask. Claude will agentically search the codebase, read relevant files, and synthesize an answer. This dramatically speeds up ramp-up time.

Workflow 2: Explore, Plan, Code, Commit

This is a versatile, foundational workflow for tackling almost any new feature or bug fix.

1. Explore: Ask Claude to read relevant files, images (like UI mockups), or URLs. Crucially, instruct it not to write any code yet. The goal is information gathering.
2. Plan: Ask Claude to create a detailed, step-by-step plan. Use the word "think" to encourage deeper consideration (e.g., "Think hard and create a plan to implement this feature"). Review this plan carefully.
3. Code: Once you approve the plan, instruct Claude to implement the solution. It will now write the code based on the agreed-upon steps.
4. Commit: When the implementation is complete and verified, ask Claude to commit the result, write a descriptive commit message, and even create a pull request using the gh CLI.

Skipping the "Explore" and "Plan" steps is a common mistake. Forcing a planning phase significantly improves the quality and success rate of the final code.

Workflow 3: Test-Driven Development (TDD) with Claude

TDD and agentic coding are a perfect match. Claude excels when it has a clear, verifiable target to work towards.

1. Write Tests: Describe the desired functionality and ask Claude to write the tests first. Be explicit: "We are doing TDD. Write the tests for a function that does X. These tests should fail initially."
2. Confirm Failure: Instruct Claude to run the tests and confirm that they fail as expected.
3. Commit Tests: Once you're satisfied the tests capture the requirements, have Claude commit them.
4. Write Code: Now, instruct Claude to write the implementation code with the goal of making all tests pass. Tell it not to modify the tests. Claude will likely iterate—write code, run tests, analyze failures, adjust code, and repeat until success.
5. Commit Code: Once all tests pass, have Claude commit the final implementation.

Workflow 4: Advanced and Automated Workflows

• Git and GitHub Integration: Claude is fluent with the git and gh CLIs. Use it to search git history, resolve complex merge conflicts, write commit messages, and even fix simple code review comments on a PR and push the changes back.
• "Safe YOLO Mode": For repetitive tasks like fixing hundreds of lint errors, you can run Claude in a permissionless mode. This is dangerous and should only be done in an isolated, containerized environment (like a Docker Dev Container) with no internet access to prevent accidental system damage.
• Headless Mode for CI/CD: Use the -p flag to run Claude non-interactively in scripts. This is perfect for automation. For example, you can create a GitHub Action that uses Claude to automatically triage new issues by adding labels.
• Multi-Claude Workflows: For maximum efficiency, run multiple instances of Claude. Use git worktrees to create isolated checkouts of your repository. You can have one Claude instance refactoring a service in one worktree while another builds a new feature in a separate worktree. You can even have one Claude write code and a second, separate Claude review and verify its work, mimicking a human code review process.

Conclusion: The Beginning of Your Journey

We have journeyed from the fundamental principles of prompt engineering to the intricate, powerful workflows of the claude-code CLI. You are now equipped with the knowledge to transform how you code, moving from a solitary activity to a dynamic collaboration with one of the world's most advanced AI systems.

The key takeaway is this: be an active collaborator. Guide Claude, provide clear context, correct it when it strays, and equip it with the right tools and knowledge through CLAUDE.md. The most effective users don't treat Claude as a magic black box; they treat it as an intelligent partner.

The workflows and techniques outlined here are starting points. The true power will be unlocked as you experiment, adapt these patterns to your unique needs, and discover your own best practices. Now, open your terminal, type claude, and start building the future.