One that I use the whole time is:

git status --untracked=no

This shows only files that are tracked. I tend to do a lot of work which leaves files that I don't want to check in lying around in my git repo, this eliminates these and lets me see exactly what I have been working on. The slight caveat to this is when you are working on a new file that you have not yet checked in ever.

This goes hand in hand with:

git add -u

Which only adds untracked files. With aliased commands this usually results in a flow like this:

> git stu

> git adu