Heres a position I was setup in today. It's all lava rock / lava flows down here and makes it extremely hard to get a good shot position. With a small flat'ish area I was able to lay prone on, and have the tripod setup on some super uneven rocks about 1.5 feet below me. I only had my 10x binos with me and wanted to get a better look at something with the scope.
I was very surprised how stable it was, although extremely uncomfortable to lay on that lava rock!
In extremely uneven terrain such as this, it makes a huge difference having tripod legs that have multiple locking positions. The promaster I'm using has 3 and I was using all of them.
It takes a while to get used to setting the tripod up on awkward terrain but if you practice it's pretty fast. Another thing to get comfortable with is the amount of tension you want on the head. I am using a ball head in the photo, and had the tension set tight enough that the gun wouldn't want to move under a slight amount of pressure. This lets me get the rifle positioned with more force, but then let everything "settle" when I'm on target.
Ya I know, I don't have a cheek weld, I only had 10 seconds on the photo timer to scramble over the rocks and get in position!