Introduction
Remember back in the day, when the whole Supporting Member thing started up? I wanted to help — but being a struggling young painter, I could only offer my time. Bill said I could paint some Bird Men in exchange for the hallowed Supporting Member icon: 
(The miniatures industry seems to operate solely on a barter system, sometimes.)
Much has happened between then and now, but the Bird Men are finally painted — and here's how I did it...
Preparation
The first thing I did was to clean up the casting with a craft knife and round file. Mold lines, flash, and all the other usual imperfections can ruin an otherwise great paint job, so try and get as smooth a surface as you can. These figures are very elderly, fragile, and made of a soft lead alloy (like they had in the olden days) so I was very careful cleaning the mold lines. In places I left a few imperfections, because a line here and there is preferable to destroying the entire figure.
Then I stuck the figures to the bases (metal discs about 1" diameter), and built up to the figures' integral base with Milliput. When that was dry, I stuck some sand on with PVA glue. (I always base before painting because it's quicker, and stops sand getting stuck all over a newly painted model.) Then I undercoated with GW White spray.