Just practise you will end up doing it without thinking. It is very useful. I remember on my skills test when i wanted to get my sunglasses out my examiner said let go if you got it trimmed correctly itll fly itself so i did. Also when you do VOR bits to find your position you need 2 hands to use the ruler. and if you do let go remember rudder induces roll so you can fly it perfectly happily with feet.
David