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
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.
Modeling Flame Effects With Hot Glue
It turns out that Hot Glue is not only useful as an adhesive, it also has modeling applications. This video shows how to use hot glue to model flames.