Modeling
Making Swamps, Marshes and Boggy Ground Scenery
This video does a good job of explaining how to make some nice looking swamps, marshes and boggy ground scenery for your wargames table.
Modeling Smoke Effects
Modeling smoke effects for wargaming miniatures.
Making 15mm Barbed Wire
The League of Ordinary Gamers has a quick and easy idea for making some good looking 15mm barbed wire.