I just found out today about git worktree[1], and I think it's a very powerful feature more people should know about, but it seems used less than it could.
Basically, you can do a working copy of the git environment without pulling the repo again, so you have only one .git folder.
A godsend if you, like me, work on gigantic repos that build unbearably slowly and want to be able to use multiple instances of the same repo at the same time.