A bit more progress on the trenches. I've applied all the gloop required and done some painting. I've also added "wriggly tin" and some small shell craters to the roof of the dug-out.
My initial thought was to add some Milliput sandbags to the parapets but then I realised that they should probably only be on the front edge, which would reduce the flexibility with which I could use the pieces. I shall ponder further.