15mm Amera Trenches and craters..
Having done a few Amera pieces for 28mm (and 15mm suitable hills) I've become a bit of a fan of the vaccuum formed plastic terrain. It doesn't mean that I know what I'm doing through, as we'll see, so you can hopefully learn from my mistakes.
After that it was a case of dry brushing a 2 or 3 applications of gradually lightening brown (and a little green on the mud slopes to add variety).
As you can see the trenches are pretty roomy, but this makes the gameplay in them easy. The height is just right for soldier heads to be peeking over the top. The Spugs are based on UK 1 pence coins, which are around 20mm wide, just for the sake of scale comparison.