Specifically, for conforming to fit as close to correct as possible, the morphs found in your model should be found in the clothing item.  So, for example, if V4 contains barbarian in her morph parameters, that same morph should be found in the clothing.  Otherwise, you will have pokethru's when the morph is dialed up.  And the way to introduce those missing morphs is by using Wardrobe Wizard or Morphing Clothes. 

Also, pose your models before conforming clothing.  In most cases, those pokethru's will not appear. 

Make body parts invisible if clothing covers those areas.