Creating a global .gitignore file allows you to ignore files across all Git repositories on your system, providing consistent file exclusion without duplicating patterns in every project. As the creator of CoreUI with 25 years of development experience since 2000, I’ve configured global .gitignore files on development machines to automatically exclude OS-specific files, editor configurations, and personal tools across all projects. The most efficient approach involves creating a global ignore file and configuring Git to use it system-wide through the core.excludesfile setting. This method ensures consistent ignore behavior across all repositories while reducing project-specific .gitignore maintenance overhead.