The 6mm Wargaming Blog has a nice set of tutorials on making terrain boards from foam tiles.
modeling
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.
Making German East Africa Buildings
Major Thomas Foolery has a photo tutorial on making WWI era German East Africa administrative buildings.
The finished product is quite impressive.
Modeling Tall Grasses
Here’s a photo tutorial on modeling tall grasses, using old brushes.
It looks like you’d be able to get quite a bit of material out of one of those cheap house painting brushes.