So you've finished your work and are ready to merge your branch back into master. Here's one way to do that very cleanly and safely:

git checkout master
git fetch --prune
git merge --ff-only origin/master
git rebase master my-awesome-feature-1234
git push --force-with-lease origin my-awesome-feature-1234
git checkout master
git merge --no-ff my-awesome-feature-1234
git push origin master

You'll remember that, right? And you'll never mess it up?

For us, we simply run:

git merge-with-master