Awareness of right hand position is crucial to achieve a great tone on your instrument. Explore the options of tone by trying different picks. You'll find a snappy, trebly attack from the thinner picks, and a warm, burnished tone from the thicker ones.
Irish musicians tend toward the thin picks , as they like the quick snap for fast picked triplets.
Experiment with different picks until you find what you like best. If you play electric, you may want a thinner pick to go with the lighter string gauges. I switch from a 1.5 Dunlop Tortex 500 Series Delrin on acoustic to a Fender Extra Heavy on electric. It's amazing what a difference your pick can make. I like to get a loud,warm sound by picking at a slight angle, tipping my right thumbnail toward the floor.