Here’s a tutorial on making trees from scouring pads.. They’re very nice looking, and it looks like a fun project, but frankly you can get nice pre-made trees from a variety of sources. Still, they’re bound to be a lot cheaper, and if you’re a do-it-yourselfer ….
Modeling
Making Town Scatter Terrain
Here’s a nice video on making a bulletin board feature for your fantasy town settings. It’s nice because it blocks line of sight in skirmish games across a fairly wide swath. The techniques used here can be applied to other pieces.
Making Buildings For Gondor
Dagorlad has a great article on the architecture of Gondor, along with instructions for building models for your Games Workshop Lord of the Rings battlegames. It’s simply amazing how he breaks down still photos from teh movies and then translates them into miniature.
Making a House From Dollar Store Foam
Black Magic Craft has some nice instructions on how to build a very nice medieval style house from dollar store foam.