I've been busy making some terrain for the game.
First up I knocked out some quick hills from "pink foam". For those of you not in the know this is a fantastic material which is extruded polystyrene. In the spectrum of polystyrene it lies between expanded polystyrene and the dense grey styrene used to make wargames figures. You can buy it from (some) model shops, but you can also buy it in large packs from DIY shops. The stuff I got is Knauff Space Board insulating foam; about £15 for 4 sheets of ~4'x2' and 2" thick.
It is hard, tough and rigid. You can cut it with hot-wire tools, but also it can be sawn with a wood saw, carved with craft knifes and even sanded with sand paper. I cut the rough shape of my hills with a saw, trimmed them with a box-cutter type knife extended to the full blade length (the ones where you extend and snap off the blades), giving me a ~ 4-5" craft knife blade.
I then finally sand down the edges to make it more smoothly contoured. The best tip for these last 2 stages is to have some figures to hand and test out a) whether they actually balance on the slope, b) whether they look plausible doing it! Anything steeper than 30 degrees is probably a non-starter.
I then give my hills (or any of my foam terrain) a coat of Johnson's Klear floor varnish to harden and protect them. An undercoat of dark brown matt emulsion (from a tester pot from a DIY shop - ~£1 each), thinned with Klear. The coat(s) of Klear will prevent the foam from melting if you want to spray it (if you do it properly!), but I find the matt emulsion method quicker and cheaper.
You can then flock straight over the brown undercoat. I use some specialised terrain making supplies for this, but there is no reason why you can't do it cheaper. I sponge on "Scatter Grip" glue - a glue that dries incredibly tacky and instead of contracting as it dries and binding flock (al la PVA), it remains sticky, thus continuing to grip the flock and stopping it from becoming brittle. I firstly scatter a fine sprinkling of mixed flock over the hill and then use a "Streugras" dispenser from Noch to "puff" static grass onto the hill. This only costs about £3 and makes the grass sit up more.
Finally you can apply a coat of spray matt varnish over the top (thanks to the earlier sealing coat of Klear).