Thanks, Joe Groff

1. git clone your existing repo
2. cd into the new clone
3. git checkout -b NEWBRANCHNAME
4. make your changes, edits, tweaks
5. cd back to the primary clone folder top level (in the folder)
6. git add .
7. git commit -m "A meaningful commit statement"
8. git push -u origin NEWBRANCHNAME
9. Hop onto github and use the branch pop-up menu to select your branch
10. Create your new pull request.

Optional step 11 is “hope you have not overwhelmed the team with your proposal backlog.”