Create and submit pull requests to GitHub hosted open source projects.
Fork project repo via GitHub UI and clone fork to local development machine.
git clone git@github.com:<user>/<fork>
Add original project repo as remote upstream
git remote add upstream <original-repo>
Set email configuration for project commits
git config user.email "<email>"
Make changes, commit and push to your fork, then update local fork to latest upstream repo state.
git fetch upstream
git checkout master
git merge upstream/master
Create pull request via GitHub UI for changes.