When I'm just locally iterating on stuff I'll usually do a git commit -m "WIP: Description of what I'm trying to do" and then git commit --amend to it. A bit more ergonomic than stashing if I want to switch branches imo. I can also go back to old versions if I want to through the reflog.

git commit --fixup some-commit is also great for if I discover things in the review for example. You can then do git rebase master --autosquash to flatten them into the commit they belong to and that way you don't have to bother with commit messages like "fixed typo". Doing fixups for small fixes is good because it allows you to keep your mr broken up into several commits without also leaving in a bunch of uninteresting history.

Can recommend checking out the --fixup section in the git documentation if you haven't heard about --fixup before.