OK, time for another tutorial, I hope this isn't teaching one's Granny to suck eggs but here's how to make really simple hills for your wargames table.
First of all get hold of some high density foam. Unlike packing foam, this material is used in construction and manufacturing roles - most familiarly for insulation - and as such is more durable, resultantly easier to work with. It is graded in terms of density from the soft Pink to the almost wood-like Brown, with this blue material in the middle.
Having marked out an inner and outer template onto the sheet with a marker pen I then used nothing more complicated than a full length snap-off craft knife blade to gradually cut through the material at roughly a 45 degree angle. Start with a shallow cut at the angle you favour then let the blade follow this cut around on successive passes (three or four times round should be enough) until it cuts through.
You can apply gentle reverse pressure (i.e. flexing the back of the board) to open the cut and make passing the blade through easier. When you've released the shape, you can tidy it up if you wish. If you are expecting particularly heavy use you may want to glue a thin layer of wood or other material to the base, but I didn't bother; this foam is really tough!
Above, the two sections could be used as a large and small hill, each is about 2.5cm (1 inch) thick. But I used a hot glue gun to stick them together instead to make a higher hill. PVA glue will work just as well but takes a lot longer to cure. Superglue is not suitable for this job.
Next, give the hill a suitable basecoat of Emulsion paint:
Having done this; you may be happy with the finish as it stands and to be fair for old school games it will look the part. But for our club, and my preference I now applied a generous layer of scatter.
Using a thinned down waterproof PVA glue paint the entire model, and then generously cover with a scatter of your choice. I would recommend light-fast flock rather than static grass, at least for the first layer, as it'll cover more completely. Give this at least 24 hours to dry fully, but you can shake off the excess after an hour or so.
Don't forget to pour that excess scatter in to a sealable tub, you want it again. I would recommend you apply a second coat of scatter for a solid finish. The second layer of PVA will seal in the first ensuring that wear and tear over time is minimised. Also in your second layer you can choose to use static grass.
Give it another 24 hours and it's ready for the table:
The 28mm Knight gives some impression of the size of the model.
The beauty of making your own terrain is of course that it becomes crazily cost effective as you increase in volume. I managed to scrounge this foam indirectly from a fabricators, but used probably only a fiver's worth to make all the hills below:
On top of that I used green paint and tools I already had, and bought £6 worth of PVA (from a budget DIY store) and scatter (from a model railway store). Each of the single tier hills has a flat top large enough for at least a minimum of one horde sized unit of 25mm based fantasy figures on top, so should well suit club usage; how large you choose to make yours, is up to you.
So, what are you waiting for, go make something!