Customizing ESLint rules enhances code quality and readability. Key configurations include enforcing consistent spacing with `space-infix-ops`, ensuring consistent returns with `consistent-return`, and promoting arrow functions with `prefer-arrow-callback`. Additional rules like `no-unused-vars` and `require-await` improve performance and prevent errors. Integrating Prettier streamlines formatting alongside linting. Documenting these rules aids team collaboration and maintains coding standards.