Watch the David Gilmour online guitar lesson by Jeff McErlain from Kings of Tone
There are two things to think about to help any guitar player sound better:
1. Play in tune
2. Play in time
Gilmour is a master at both, his bends and vibrato are impeccable and his time is excellent. These are two elements of music that your average listener can immediately pick up on. Most people don't care or know what a scale or triad is, all they care is if it sounds good, but if you are out of tune or they can't tap their foot you are in trouble.