My buddies and I regularly brew 15 gallons of all grain ales and usually have a starting gravity in the range of 1.060. As consistently, our fermentation seems to always stop between 1.020 and 1.019. Occasionally we get it to ferment a bit lower, to 1.016 or so. Our beer tastes good but seems to be a bit "starchy." We usually mash at 149, then raise the temp to 155, then raise it again to 165 and sparge for 60-90 minutes with boiling water. We also use about 3/4 gallon of yeast starter. I should mention that we our grain bill is usually about 30lbs of 2row and a couple of pounds of crystal 60. Hops can vary.
Any suggestion as to how to get our final gravity down a bit for a dryer beer? I would be happy with something between 1.015 and 1.010.