I had a restoration build that used Spirit Light Weapon which seemed to help a lot. It made it so i didn't have to heal as much, and its great at relieving pressure. Also, i used the assassin skill, Shadow Refugee, for myself and if need be, i would use Spirit Light Weapon on myself. That way you don't waste near as much mana healing yourself. Also, my last tip if the first 2 I said get shot down is bringing one of the restoration pots. Keep them up as much as you can, and when in battle, drop them if you run out of energy so that you will have back up energy from your equips. I run a build like this on my Ritualist, and I have beaten almost all the campaigns so i think its worthy.
Good luck