The first thing I did when trying to learn to hover was to fly a perfectly vertical up line. Using rudder, elevator, and ailerons I concentrated on the small adjustments for absolute vertical. Usually right rudder was needed a small amount to hold it straight. Then, I began to reduce power and slow the vertical ascent. The slower it climbed, the larger deflections of the control surfaces were needed as there was less air flowing over them. You must keep the empenage under the nose with quick corrections of rudder and elevator. The farther off they are, the larger the correction, so get them before they get too far out with small correction.

Its like balancing a baseball bat on your finger. Once you get it, you got it.