Thanks Pentaro, and everyone for the kind comments. Some of the markers were made for the TooFatLardies "Through the Mud and the Blood" rules to denote "shock". These rules require a player to keep track of "shock" inflicted on his or her troops. Some people use micro-dice placed by the side of the figures to keep track of "shock", but I thought it looked better to have a casualty figure to place the micro-dice on top of rather than having the micro-dice rolling around the terrain as the figure moves. I built the bases so there's generally a square nook or cranny that the micro-dice fits into.
One of the markers (with the shredded telephone wire) gets placed when a "Communications Down" card is drawn by trench defenders, preventing the defenders calling in an SOS barrage during a trench raid.
The destroyed MG pit is to slot into a purpose built space on a wooded terrain board. There'll also be an intact MG base when I get around to finishing it

The bases get interchanged when the attackers take the position. It's really just for appearance.
The barbed wire was really easy to paint. Just spray paint the barbed wire matt black, and dry brush different rust-coloured shades of dark brown, red brown, and orange on top. For some of the trench posts, I mixed the rust-coloured paints with some bicarbonate of soda to get a nice corroded, badly rusted look to the iron. The barbed wire is from Forgeworld. It's lethal, and keeps digging into your fingers when you touch it. I'd not recommend it for any figures you're going to be using a lot - far better use the twisted wire you can get from Antenoctit or Rob at Scarab.