Don't know if you have Krylon brand spray paints in the UK but you probably can find cans of spray paint for camouflage - and, if so, in dead flat. I use it as a base and then do a heavy wash of some brown, like burnt sienna, from the craft store (tons cheaper, like twenty times per ounce) and then normal painting on top of that. Works pretty well for me. Not searching for art work but playable figures. Now if I could just paint twenty times faster.