Writing safe and maintainable JavaScript code is essential in creating high-quality software that can be easily maintained and updated over time.

1. Use strict mode: Strict mode enforces more stringent rules for JavaScript code, which can prevent a variety of errors that might otherwise slip through the cracks.

2. Avoid global variables: Using too many global variables can lead to name conflicts and make it difficult to track down bugs.

3. Keep functions short and modular: Breaking complex tasks down into smaller, reusable functions can make your code more readable and easier to maintain.

4. Use meaningful variable and function names: Descriptive names can make your code more readable and help prevent confusion.

5. Don't ignore errors: When errors occur, it's important to handle them properly to prevent your program from crashing.

6. Comment your code: Comments can help explain what your code does and why it does it, making it easier for others (and your future self!) to understand and modify.

7. Use consistent formatting: Consistent formatting makes your code easier to read and maintain, and can prevent errors caused by typos or missing characters.

By following these best practices, you can create code that is easier to read and maintain, with fewer errors and a better user experience.