Q: Somebody told me that I’m not allowed to change the .orig.tar.gz tarball and that it should be identical to the one that is used upstream. I have a real need for it, how do I do it right?
A: Check out this chapter in the PackagingGuide. It has extensive information on how to do it right including side-cases and solutions.
Q: Do you have some kind of example package that I can try to learn from?
A: This page on the PackagingGuide wiki as exactly what you’re looking for. (If you know of a package that is really done well and people can learn from it, consider adding it.)
Q: I posted a workaround or simple fix on a bug report (or on the forums). How do I get it integrated into Ubuntu?
A: First look up how to generate a debdiff. Then follow this quick guide to get it included in Ubuntu.