To unstage all files that you might have staged with git add using:
git reset
To revert all local uncommitted changes (should be executed in repo root):
git checkout .
You can also revert uncommitted changes only to a particular file or directory:
git checkout [some_dir|file.txt]
Yet another way to revert all uncommitted changes
git reset --hard HEAD
This will remove all local untracked files, so the only git tracked files will remain for that use:
git clean -fdx
WARNING: -x will also remove all ignored files, including ones specified by .gitignore! You may want to use -n for the preview of files to be deleted.
Reference: https://git-scm.com/docs/git-clean#Documentation/git-clean.txt--X