- Mix wood glue with water to make it all milky (1:5 should do it) and cover large parts of the hill in the mixture, leaving patches of painted sand showing to resemble dirt (we're not make a lawn, after all).
- Cover the mixture in green flock to resemble grass, leave it to dry for a while before blowing the excess flock away. I recommend using at least two different colors of flock to make it look more realistic (since grass is usually a few different shades of green)
- Once the glue is dry and the flock is stuck to the hill, the project is more or less complete. However, I like to add a few details to make the hills stand out from each other and look less barren. The following stage is entirely optional but can add a lot to the overall appearance of the hill.
- Pick out the largest sand corns on the hill with a few different colors of grey (Codex Grey and Fortress Grey usually look good together) to create the sense of small rocks on the hill. It makes the dirt stand apart from the grass and draws the eye in.
- Glue a few bits of foliage to sections of the hills in order to create the appearance of bushes and, if you have any to spare, stick a few small trees to one side of the hill. It looks natural and it creates another strategic function in the game if one side of the hill blocks line of sight for artillery.
- Once you're satisfied with the look of your hill, mix a tiny but of wood glue with plenty of water (at least 1:10) and fill a spray bottle with the mixture. Then spray all the entire hill and leave to dry. This will make the flock sturdy enough on both sides to survive the rigors of gaming longer.
That's it! The hills are completed and ready for gaming. Here's how they look on my own gaming table, alongside a few forests, boulders and other pieces of scenery. Yes, I know, I really ought to do something about all those unpainted models.