Best practices in Apex development help maintain code quality, improve performance, and ensure scalability. Here are some key best practices to follow:

1. Governor Limits Awareness: Salesforce enforces governor limits to ensure fair resource allocation on its multi-tenant platform. Always write code with governor limits in mind to avoid hitting limits, which can lead to exceptions and performance issues.
2. Bulkification: Write your code to process records in bulk rather than individually. This ensures that your code can handle large data volumes efficiently and helps prevent hitting governor limits.
3. SOQL and DML Bulkification: Perform DML operations and SOQL queries outside of loops whenever possible. This reduces the number of SOQL queries and DML statements executed, improving performance and reducing the risk of hitting governor limits.
4. Selective SOQL Queries: Write selective SOQL queries by including filter conditions in WHERE clauses to limit the number of records returned. This improves query performance and reduces query execution time.
5. Error Handling: Implement proper error handling in your code to gracefully handle exceptions and failures. Use try-catch blocks to catch and handle exceptions and provide meaningful error messages to users.
6. Code Readability and Maintainability: Write clean, well-structured code that is easy to understand and maintain. Use meaningful variable names, comments, and proper indentation to improve readability.
7. Use of Design Patterns: Familiarize yourself with design patterns such as Singleton, Factory, and Dependency Injection. Applying design patterns can help you write more modular, reusable, and scalable code.
8. Test Coverage: Always write unit tests to ensure adequate test coverage for your Apex code. Aim for at least 75% code coverage for all Apex classes and triggers.
9. Separation of Concerns: Follow the principle of separation of concerns by organizing your code into separate classes and methods based on functionality. This improves code maintainability and reusability.
10. Use of Asynchronous Apex: When performing long-running or CPU-intensive operations, consider using asynchronous Apex (such as Queueable or @future methods) to avoid hitting CPU limits and provide better user experience.
11. Avoid Hardcoding IDs and URLs: Avoid hardcoding record IDs, URLs, or any other sensitive information directly in your code. Instead, use custom settings, custom metadata, or hierarchical custom settings for configuration data.
12. Avoid Nested Queries and Loops: Minimize the use of nested queries and loops, as they can lead to performance issues, especially when dealing with large data volumes. Instead, try to optimize your code to use efficient data retrieval and processing techniques.