I really, really like Clay Statues.
My mist elven necromancer (lvl 14, 62DV 17 PV) spends her time reading spellbooks in animated forest - all the while her Clay Statue slave kills Trees, generating more and more spellbooks for her to learn. You need to level up the statue to about lvl 35 (which is not hard at all in the big cave, especially if you are farming herbs there) first, but after that Animated Forest becomes a treasure trove.
Now if only that generated amulet of life saving as well...