1. A hill. Despite forty years of spoddery I have never built a hill. Instead I have used commercially available ones. However as these were designed for 15mm and I now play only 25/28mm they look a bit sad. So I have started building one.The choice was between a realistic, gradually-sloped one and a steep sided 'step' hill. As figures won't stand on anything but the shallowest slope, instead toppling over or slithering to the bottom, it is a step hill.
It was cut from pink insulating foam - a tenner for a massive sheet from B&Q - and hacked to a rounded shape using a steak knife. Any serrated knife would do. It was then sanded a bit so the edges weren't quite so sudden. As the plan was to spray it with pound shop paint the foam had to be protected from the spray, which would dissolve it. So I covered it with papier mache - specifically painted it with PVA and stuck on torn-up newspaper and painted on more PVA. That took days to dry. After that I sprayed it - the result is below, with a Reaper Bones figure for comparison.
3. Barriers of some sort. In the pound shop there were some cheapo Jenga-type blocks. They're smaller than real Jenga ones but much cheaper. I thought they could be some kind of walls or similar. Maybe in several varieties. For example a block clad in corrugated paper and topped with sand held on with PVA might do as a makeshift HESCO type barrier made from two corrugated iron sheets held upright by posts and then filled with sand or earth. A block covered with matchsticks cut to length and topped with sand would be the same but made of wood rather than corrugated iron. Maybe doll's house brick paper, which I think I saw in the craft shop, could be stuck on to represent a brick or stone wall. Covered with PVA and sprinkled with sand they could be cast concrete walls, roadblocks et cetera. And so on. Being the small size they are they could be used in different configurations to be various emplacements, bunkers and similar. This one is still to be fully though out.
4. Storage tanks. These were cheekily knocked together at work. They are toilet roll tubes, the kind from a dispenser rather than the domestic variety, with a circle of cardboard for a top. The inspection hatch, filler ring or whatever on top is the foam circle that you get on a spindle of CDs. That was glued on and the whole lot smuggled out of work. At home the tube was smeared with, you guessed, PVA and corrugated cardboard wrapped around it. Elastic bands held that in place for a few days until they dried and were sprayed, as below.