> I'm thinking now if I ever want to do footnotes or number > headings or whatever, I should instead customize one of > the existing macro packages.
If you're doing this (mostly) for fun and to really learn troff, I suggest you try to cobble together your own macros for this first. Then you can choose to expand them or later select an existing macro package to modify, but in either case what you learn with a simple macro package and the techniques to deal with problems that repeatedly occur in document formatting will help you a lot in the future. A good starting point are the tutorial examples in the old Bell Labs Computing Science Technical Report #54 (http://cm.bell-labs.com/cm/cs/cstr/54.ps.gz).
