Here's a cool rebasing technique that can save some time. I don't recommend using this if you aren't familiar with using rebase, there's probably a lot of ways to shoot yourself in the foot here.
Say you have a big pull request, with a bunch of commits, that look like: (oldest first, like in interactive rebase view, not git log --oneline view)
c129b43 Implementation of FooClass
3ffa239 Tests for FooClass:fizzle()
b3512ab Use FooClass::fizzle() to fizzle the frobnulator.