I was just watching the velocidrone tuts, and they point out that at a high camera angle, the throttle has very little effect on the height compared to a lower angle, which makes sense because of the balance of the two force vectors.
It helped me to imagine the palm of ones hand is the drone and so you're going in a straight line with your fingers pointing slightly down, now drive that hand around a curve nice and smooth and just watch yourself apply yaw and roll automatically as you imagine the thrust vector at right angles to the plane of your hand while also imagining that the object also has it's own momentum to deal with. Here you're using the left stick to push yourself through and around the corner.