Ryan Scow has an article on making balsa strips look like realistic timbers.
Modeling
Fantasy Banners
The City of Solis website has some good looking, hand drawn banners that you can cut out and use with your Warhammer, Chronopia, or other fantasy armies.
Scratch Build Modular Catwalks
Here’s a video with advice on building modular catwalks. The techniques also can be used for a variety of science fiction projects.
Scratchbuilding Weapons For 1/64 Battle Cars
If you’re into post apocalyptic games such as Gaslands or Battlecars, you may find this guide to scratch building weapons for 1/64 battlecars useful.
Modeling A Medieval Fantasy Inn
Here’s a good video on modeling a medieval fantasy inn.