I'd like to create a new remote branch for later use.
The most commonly suggested way seems to be:
git checkout -b newbranch origin/startingpoint
git push origin newbranch
push demands a local ref, though it seems to me now that's a bit arbitrary. But it doesn't care what the local ref is called, you can say what remote name you're pushing to directly, so:
git branch junkname origin/startingpoint git push origin junkname:newbranch git branch -d junkname