You should first think about some of the unique helmets that the Witch Doctor has access to within the game. This is one of the best features for their class, since they provide a boost to many of their skills and magical abilities. Whereas most other players will wear helms and other non-magical helmet items, you can have access to voodoo masks. These items provide a considerable boost to your skill, so keep an eye out for them throughout the game. You will be guaranteed to get more advanced masks as you advance in the game. Try to locate some of the best masks at each level, which may include Zunimassa's Vision.
Don't forget that you can also get other armor components as well. This will be vital if you want to keep your defense up throughout the course of different levels. Without some of these unique or magical items, the Witch doctor character may actually be somewhat weak. If you keep an eye out for some of the different items available to you, then you can get linked up with the right skill boosters. You may want to look for Vile Ward items rather than shoulder items, since these often come imbued with different stat enhancing benefits.
There are also many different amulets that are available for sale throughout the game. Though you can feel free to buy any of them, you should pay careful attention to the different kinds that provide a specific benefit to the Witch Doctor class. It will help to do a little research and find out which of these will be best suited to your needs. Think about whether you can get linked up with amulets like Tal Rasha's Allegiance, which are proven to boost the stats for a Witch Doctor build. Just focus on integrating the items you may need to boost your skill set as you move on through each section of the game.
Finally, there are also a myriad of different weapons that you could choose to use alongside the Witch Doctor class. Though they can use many different weapons, they are best fitted with certain kinds. Many players seem to prefer using the ceremonial dagger, since this is specifically made to boost the stats of the Witch Doctor. It may be best used in conjunction with some of the different abilities that this character can display.