modeling
Modeling A Void Shield Generator
Here’s a tutorial on scratch build a void shield generator. While intended for Warhammer 40K, a model like this could be used in a lot of science fiction games.
Modeling Giant Science Fiction Crystals
Here’s a video tutorial on modeling giant science fiction crystals. The intent is making large, emerald style crystals for Necron terrain, but I can see these in any number of settings, including pulp action lost worlds.
Making Counters For Games
The League of Ordinary Gamers has a tutorial on making counters for your games.