A new build I have been working on is based on infinite bears and spirit barrages.
This build is heavily dependent on Rush of Essence, what this passive does is give you mana regen each time you cast either Haunt, Horrify, Mass Confusion, Soul Harvest, Spirit Barrage and Spirit walk. When looking at this build I utilize 4/6 of the required skills for rush of essence. The best part of this build is that you simply need to cast these spells, without even having a target the mana regen will still kick in.http://us.battle.net/d3/en/calculator/witch-doctor#gfdUeT!fce!ZcYaaa
Spirit Barrage - Well of Souls is a great skill that can do a lot of damage. The base of this build relies on spamming this skill, for the purpose of using the passive rush of essence. This passives stacks the mana regen on top of what you already have so technically the more AS you have the higher you can get your mana regen. The 3 extra spells that do 65% of your damage, these will not overwrite each other. For example if you cast 2 Spirit Barrages very quickly 6 bursts of damage will fly out.
Zombie Charger - Zombie Bears is obviously one of the if not the most powerful WD skill, the only real issue is mana consumption but with this build there is no issue with mana.
Soul Harvest - Soul To Waste I use this skill for a more permanent damage buff, it also procs Rush of Essence.
Spirit Walk - Jaunt is my personal favorite skill and has saved me in a lot of BAD situations, this also procs Rush of Essence.
Haunt - Consuming Spirit This skill is the one you can play with, I prefer using it to gain life against reflect damage mobs so my bears don't crush me. It also procs Rush of Essence
(Other ideas for this slot)
Mass Confusion - (any) Just a good skill, when you're in high MP's it can be a life saver. It also procs Rush of Essence
Horrify - (any) is also very good for fighting elites, even if they run off screen Spirit Barrage can snipe them very easily. It also procs Rush of Essence
Gargantuan - Humongoid is my favorite Garg because of his sustained DPS and cleaving abilities. In this build it can easily be swapped out for Zombie Dogs - (any).
Rush of Essence is the entire build, this fantastic mana regen ability stacks each time you cast one of the spells specific to this skill. AS scales very well with this... LETS DO SOME MATH. Rush of Essence increases regen by 49 for 10 seconds this means its giving you a base regen of 4.9 per second per cast. 49/10=4.9
If you're AS is about 1.5(mine) that means in 10 seconds you can cast spirit barrage 15 times not including haunts.4.9*15=73
BASIC MATH BUT YOU GET THE PICTURE I HOPE
Blood Ritual is also very good for this build not only giving you 1% HP regen but reducing the cost of your spells by 15%, this allows for a lot more casts meaning a lot more mana.
Spirit Vessel im pretty sure any bear spec should have this.