Watch the Pulling Maximum Tone online guitar lesson by Marcy Marxer from Mandolin for Guitar Players
Try a selection of picks to experiment with tone and gravitate to the sounds of your choice. Pick thickness makes a huge difference in sound. Try changing the angle of your right wrist, too. I gravitate to heavy picks because I like a clear, direct and full tone without much pick noise but I always keep a selection of picks in my bag at gigs. A thin pick will provide a lighter jangly sound which can be perfect for some tunes. First start by getting the fullest sound you can pull. You can always dial it back or thin it out if you want to.