Three things: If you submit a bug and it gets fixed, verify that it was indeed fixed, and mark it as such. Close the loop. Related to point #5, if you do file

Three things: If you submit a bug and it gets fixed, verify that it was indeed fixed, and mark it as such. Close the loop. Related to point #5, if you do file a bug, don't just file it and walk away, even if you do provide lots of helpful information. If it's a particularly tricky bug the person working on it will probably ask you for more information, especially if it's only occasionally reproducible. #10 is important whether you're using an open source project or not, but it's especially true if you aren't going to do #9. It might be enough to keep the author working on the project.