Maybe a little more downthrust is helful, if it's fliping to it's back, or less downthrust if it's nosing over would help. But from what I see it's a trial and error method, in the computer it's almost impossible to simulate all the things that happen in an airplane, so it's much easier to hover in a sim than on real life. A sim is great for learning the proper coordination for mainting a fairly good hover. I know this by own experience, after spending a month practcing hovers on the sim, when I got to fly my SPAD (now retired) I hovered it 2 feet from the deck at my first attempt at hovering on the real life.....But to find that "sweet spot" in real life is basically a trial and error method.

Hope this helps....