I concur... For me it was just a LOT of practice in the sim. I basically gave up at one point, but then suddenly a few days later it all of the sudden "clicked". I don't know how to describe it, but it went from being able to hover for 3-4 seconds, to being able to hover indefinately. Such an awesome feeling. Pick the largest 3D plane in RealFlight you can find as it's slower and easier. I used a 40% Edge to learn on. Then trying it on a real plane on the deck was probably the most joyful/memorable flight I've ever had. I believe I was jumping up and down while hovering down low that first time.

Practice makes perfect. There's not really a guide, just practice. For belly hover just remember to push rudder to the lower wingtip and you'll be golden.