Sync'ing a git / GitHub fork.
I need to do this fairly frequently, and for some reason I can never remember the steps, so I'm writing it down!
$ git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
$ git fetch upstream
$ git checkout master
$ git merge upstream/master
Make your edits, etc. Push (this will push to your fork), make pull-request. Next time you need to sync the orogin, start at the '
git fetch upstream' step.