The 1000 Foot General blog has a good tutorial on building rocky desert hills that are suitable for a wide variety of settings.
terrain
Turning Old CDs Into Scenic Monster Bases
Old CD are of use as bases for wargames terrain, and for larger figures, such as monsters. Here is a tutorial on turning old CDs into Scenic Monster Bases.
Making Stylized Wargames Hills
Here’s a good video tutorial on making the sort of terraced wargames hills which are not particularly realistic, but which are eminently practical from a gaming perspective.
How To Make Craters
This video tutorial teaches a technique for making craters. It’s a useful thing for modern, post modern and full-blown science fiction games.