Hi Andrew!
You mean as in doing a pull request on github?
I have always been on the receiving end of those (long story but suffice it to say that a project I contribute to uses github (as a read-only copy of our main repo) and I commit stuff for others) and not on the sending end but there's a beginning to everything and I am sure I will figure out how to do it...
Thank you and have a nice day!
Nick