Watch the Fretting Hand online guitar lesson by Brad Carlton from Guitar Lab: Super Sustain
This lesson covers fretting hand dampening which truly brings an element of finesse to your touch. As a starting point for learning this technique think of touching a note as placing a finger against the string but not depressing the string against the fret. This is your dampening posture which needs to be a part of your muscle memory so you know what it should feel like after fretting a note and then applying fretting hand dampening. Part two of fretting hand dampening is the gentle release of the finger perpendicular to the string so as not to disturb the string and cause it to vibrate. We all know what it's like to lift a finger off the string and get what I would term a ghost pull off. I always tell people that releasing a fretted note is a two-part affair: a quick release of the muscular tension in the fretting finger at the point where you want the tone to cease, and then a slower, gentle lift of the finger off the string. You can actually learn how to do this at a pretty quick tempo but you must practice slowly at first.