Modeling
Making Hedges From Scouring Pads
These really look good.
Making Terrain Boards From Interlocking Foam Tiles
The 6mm Wargaming Blog has a nice set of tutorials on making terrain boards from foam tiles.
Modeling Camouflage Netting From Gauze
Plastic Warriors has an article on modeling camouflage netting. The key ingredients in this project are fine gauze and super glue.