Show ignored files in a git repository

Another option that’s pretty clean (No pun intended.):

git clean -ndX

Explanation:

$ git help clean

git-clean - Remove untracked files from the working tree
-n, --dry-run - Don't actually remove anything, just show what would be done.
-d - Remove untracked directories in addition to untracked files.
-X - Remove only files ignored by git.

Source