Got to hell mode with my WD, and kind of struggling to find a good build. I've had the most success with explosive frogs and firebats, and of course spirit walk and soul harvest.
This is roughly what my build has been, some skills have been swapping a lot, trying out different things. (had some success with grasp)
http://us.battle.net/d3/en/calculator/witch-doctor#WcdUbk!ZYV!aaZZZY
Gear-wise I'm doing mostly fine, damage output is fine. Biggest problem so far has been running out of mana, no matter the build.
Any advice?
With my Witch Doctor mana is furthest from my thoughts. It's been nearly impossible for me to run out. I use Spiritual Attunement and Vision Quest for passives. With Vision Quest you just pick other skills that will be on cool down, so that you have 300% mana regen. I have Gargantuan constantly on cool down, and Fetish Army. I also use Spirit Walk and Soul Harvest. So basically when I come to a group I spirit walk and soul harvest then get myself to a good spot and spam Firebats over and over. With 300% regen it's impossible to run out. My main single hit skill has been Spirit Barrage. With the mana rune I can't run out even without Vision Quest going. I also have a mana regen weapon and mojo, so find some of those.