So there is an open source project on GitHub. And you forked it already. And there is this bug XYZ you would like to fix, throught a pull request. This post is a short checklist on how to do it.
Use Feature Branches
Get ready to work with feature branches. Those isolate the work you do for a particicular pull request from all the other things you want to contribute.
Create a branch for the issue XYZ where you will implement the bug fix.
git checkout master # starting point is your master
git checkout -b XYZ # create and checkout branch XYZ
# you are going to work on
Do non-stop coding. All day all night. Mind coding styles of the project you are working on. Use the right tools.
At some point you are done.
git log # check what you have done
Cleanup using git rebase
You may have produced several commits. And there may be typos in your commits. Or you commited try to fix bug (1..n). Squash (i.e. combine) all of your commits and give it a nice commit message. This makes it easier for reviewers to see the actual changes and to eventually merge the pull request.
Your tool for the job is interactive rebase. It allows you to reword, remove, combine and alter commits.
git rebase -i HEAD~n # n=number of commits from HEAD
# you created
This pops up an interactive console
pick 906eb32 yea, nearly done
pick 8a45bb9 ok, late night trying again
pick b86deaf got ya
Combine all of your commits into one by assigning s or squash as the rebase operation.
pick 906eb32 yea, nearly done
s 8a45bb9 ok, late night trying again
s b86deaf got ya
Finish the job, i.e. press [ESC], [:wq] to write the changes and close the editor.
You will be asked to write a commit message that describes everything you did. Make it a good one (check your projects contribution guidelines, too).
Again, finish the job with [ESC], [:wq].
You are done and your changes are ready to be published!
Push, Pull Request, restart
Push the stuff to your remote:
git push origin XYZ
If you have pushed parts of the work before, you may need to override these changes by applying force (-f):
git push -f origin XYZ # overrides history on the server
# branch so take care what you do
Create a pull request from your origin/XYZ branch to the OSS projects development branch.
Switch back to your master branch
git checkout master
And create a new feature branch for this AABB issue you wanted to fix for such a long time already.
git checkout -b AABB
There is more
There exist many more resources worth checking out on the topic: