I seem to be doing this a lot:

$ git branch --show-current
master
$ git checkout my-feature-branch
$ git rebase master

Except that master might be another main branch. There should be a way to just say, “rebase on whatever I had previously checked out”. In some contexts, ORIG_HEAD points to what the HEAD was previously, for some definition of previously. It appears that git checkout sets ORIG_HEAD, but I haven’t found any documentation on this nor have been able to trace this in the git source code. But it appears to work. So it would be:

git checkout master
git pull
git checkout my-feature-branch
git rebase ORIG_HEAD

It would be nice if ORIG_HEAD had a shortcut like @ for HEAD. Something to think about.