Here’s a short photo tutorial on making a dark ages livestock corral, which is perfect for your SAGA games.
modeling
Making Magnetic Terrain
Dux Humunculorum has a post on making magnetic terrain. The idea is to keep your bases from slipping off the slopes.
How To Build A Hollow Hull For A Larger Model Ship From Scratch
Wargaming Miscellany has an article on building a hollow hull for a larger-sized model ship.
Making A Sheet Plastic Vacuum Former
With your own homemade sheet plastic vacuum former, you can (easily?) reproduce lots of different things for your wargames table, especially terrain features.