I wanted to make a ruined fort or watchtower on the hill but it would be too impractical for gameplay. Instead, I glued some 'flagstones' down to the hill to give them some color and character.
Step 1: I glued the hilltop piece to the hill base with woodglue. I cut up a cardboard box into rectangles and glued them into a flagstone pattern on the hilltop.
Step 2: After the glue was all dry, I put a layer of Mod Podge over the 'flagstones'
Step 3: Then I painted the entire surface with my earth tone latex paint.
Step 4: I guess my camera minion was lazy, because I only have the final picture. I drybrushed the flagstones grey and then white, and flocked the hill. I used a greener flock on the hilltop to help it stand out.