Personally I also use git to control any major projects. By "major" I mean anything I don't want to lose, compared to a small example I knock up for the forum.
Install git, then using the command line (console) navigate to the appropriate directory.
git init # <--- do this once
git add *.ino # <--- also add .cpp and .h files as appropriate
git commit -m "Initial commit"
Then after making major changes commit what preceded:
git commit -am "Improvements" # <--- "add" changes, commit them with message
Now if you ever go "duh!" because a change made things work less well you can revert back to a previous version. Plus you effectively have a "backup" in the .git subdirectory.
And you can find what changes you just made: