I agree with Luke 3D, you've gotta get the plane vertical. I see too many people afraid to get completely vertical, and the plane is mushing forward and constantly stalling on the wing making for a wild dance, but no real hovering.

... and don't forget the CG, the further back the easier the hover. I have a Su-Do-Khoi with a normal setup and it does a pretty good hover, but I also have a Top Cap with the CG waaaaaay back. Its a little hard to fly straight and level, and hard to land without ballooning, but it sure does like to hover!