What you'll need:
Paint (I used acrylic, it went on smooth but dried rough so I'm sure there's a better paint to use for it, I'm just not that knowledgable of paints. If there is please share in comments)
Possibly a soldering iron
Step 1: Choosing A Mini figure
There are some other sci-fi types out there, my favorite was part of series 11 I think. It's the one with the bulky shoulders.