Pijlie’s Way blog has a series of posts on how he built a fabulous 17th – 18th Century Tavern.
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.
Building A Ruined Tower For $1
This video shows a neat build of a ruined tower terrain piece for your wargames table. It would work well for all sorts of genres and periods.