Barges — of the sort used to transport troops and supplies — can be used as central pieces in games set in a wide variety of periods. Here’s a set of instructions for making a barge from a date tray.
Modeling
Working With High Density Polystyrene
Manorhouse Workshop has a set of three tutorials on making wargames terrain from high density polystyrene (insulation board).
Old School Warhammer Fantasy Basing Tutorial
Realm of Chaos has a tutorial on basing using techniques I gleaned from back in the 1980s when I first started playing Warhammer Fantasy.
Wargames Terrain Inspiration
Here’s a Pinterest account with hundreds of photos of wargames terrain. There lots of inspiration here.