For simple changes, you can just `git diff` it to a file, put that file on a pastebin and share that link with any communication tool (or share the file directly). `git format-patch` is more where you want to share the commits (message and all). And you're not tied to using email. It's just a collection of files that you can share using whatever.
The only Git Gui I've used extensively is magit, and patch worked fine. It's very much like cherry picking commit or doing merge. There can be conflict so be sure to use `--3way` flag.
