To ensure code quality, it is important to measure code metrics and follow best practices. Some common code metrics and quality measures include:

1. Code complexity: Measure the cyclomatic complexity of your code using tools like SonarQube or Checkstyle. Aim for a lower complexity score to make your code more readable and maintainable.

2. Code coverage: Use tools like JUnit or Cobertura to measure the percentage of code covered by tests. Aim for a high code coverage to ensure that your code is thoroughly tested.

3. Code maintainability: Apply best practices such as avoiding long methods, reducing code duplication, and following coding standards like naming conventions and code formatting.

4. Code comments: Document your code by adding clear and concise comments. Comments should explain the purpose of the code, any assumptions or limitations, and any complex business rules.

5. Error handling: Properly handle exceptions and errors in your code. Use appropriate try-catch blocks and handle exceptions gracefully to prevent crashes and improve the reliability of your code.

6. Code reusability: Write modular and reusable code by breaking larger tasks into smaller, self-contained functions or modules. This allows for easier testing, debugging, and maintenance.

7. Code performance: Optimize your code to be as performant as possible. Use efficient algorithms and data structures, avoid unnecessary loops or recursion, and analyze the time and space complexity of your code.

8. Code documentation: Create comprehensive and up-to-date documentation for your code. Include information about the purpose, inputs, outputs, and usage of your code.

9. Code review: Have your code reviewed by other developers to get feedback and catch any potential issues. This can be done through pair programming, code walkthroughs, or using tools like GitHub pull requests.

By measuring and improving these code metrics and following best practices, you can ensure that your code is of high quality, readable, maintainable, and performs well.