Here’s a nice photo tutorial on making Jungle Terrain.
The key ingredients are trays of plastic plants and mdf.
modeling
Modeling Small Water Craft
Anton’s Wargaming Blog has a tutorial on modeling small watercraft, such as lifeboats.
Making Incidental Terrain
Incidental terrain are those small bits of bush, rock outcroppings, and other features that serve to break up the look of a flat gaming table. The Battlefields and Warriors blog has some tips on creating battlefield incidentals. I really like what he has done and realize that I don’t have enough on my own tables.