I have a lv36 Necromancer
...You probably don't need to know about it anyways.
A Circlet with +2 P/B, Faster R/W, FCR, and life... Gamble gamble gamble!
Amulet should also have something of the like...
Other gear you might want to look into:
3-PGemmed Kite Shield (Against various elemental opponents)
Cleglaw's Shield (Against poison)
Infernostride (Against fire)
Etc etc...
I find some of my toughest opponents to be high-level (80+) Barbarians that WW through your Bone Prisons and have lots of life... Enigma characters are extremely hard to kill unless you're able to get a lucky string of hits on them.
Other Bonemancers are also hard to kill too; I use a staff with charges of Teleport on switch to get out of Prisons; forget the level requirement though... Doubt it's lv30.
~Mystic~