I had private education for years on the classical guitar so everything was kind of strict concerning posture and such which is kind of rigid in comparison with how I play guitar now (which is for shit). Anyway, I probably could read sheet music if forced at gunpoint but what I carried away from the experience is:
Repetition, start at slow tempo and practice with a metronome as you progress, don't speed up until you can get a passage just right, do your exercises allthough they are dull and bore you out of your mind. Rest your hands regularly and allow your muscles to unclench by gently shaking your our some such. Oh and wash your hands before playing your instrument.
I don't necessarily keep to all that, though.