Personally, I think ticket description is more important than code, so I always create a ticket first. Unfortunately, github's issue tracker doesn't allow attachment, and thus it inadvertently promotes this "pull requests from out of nowhere" behavior.

Call me old fashioned, but I still like ticket + attached patches way more than anything else. Recently, I stumbled upon a Google Code project with several defect issues. One guy commented on each of the issue with a link to his github fork which he has applied the fixes. I clicked the link, and found that the fork has been deleted. What a waste.