Take the High Ground has a photo tutorial on making some impressive looking smoke markers.
Modeling
Modeling With Birch Tree Seed Pods
Game designer and gamer extraordinaire John Hill (Squad Leader, Johnny Reb) once told me that “nature recreates itself in miniature” in response to a request for advice on terrain building. This advice for modeling with Birch Tree Seed Pods is a great example.
Scratch Built Shanty Buildings
Here’s a page with some good photos and nice advice on making shanty buildings.
Making Bocage Tutorials
Here are a series of videos on making bocage hedgerows: