Probably you're using a .gitignore file for every project. If you find yourself creating a .gitignore file for the same files on every project you should use a global .gitignore file.

You can specify the location of the global .gitignore file with this command: git config --global core.excludesfile '~/.gitignore'

If you're on osx you can add files such as .DS_STORE, Thumbs.db, ... PhpStorm-users could add .idea.

My global .gitignore file can be viewed on github.