Hi Ivan,
great that you are preparing your work for the inclusion into our main development tree!
Once you created a branch based on current genodelabs/master and cherry-picked your changes on top of that branch, it's all set. No additional steps are needed. Just open an issue and mention the corresponding commit IDs or a link to the branch. Personally, I prefer opening plain issues over the pull request feature of GitHub.
It turned out to be a good practice to reference the issue number from the commit message. For example, by stating "Refers to issue #1234" (including the hash symbol), the commit ID will automatically appear in the discussion of issue #1234. If the commit message contains the magic words "Fixes #1234", Github will automatically close the issue as soon as the commit enters one of the genodelabs/staging or genodelabs/master branches. That's pretty convenient.
Cheers Norman