+1 for checking for complete conversion, it isn't unusual for me to find that a 60 minute mash hasn't fully converted the starches to sugars. Other things that can help improve efficiency are getting your water right before mashing, some of us also feel that malt conditioning prior to grinding helps our efficiency. How much water loss to absorption are having? If you're losing much more than 1/10 of a gallon per pound of grain, you might get some improvement from allowing for a longer run-off from mash and sparge, assuming you have time to spare. I use a grain bag in a mash cooler & batch sparge, and am one of the heathens who squeezes as much wort out of the bag as is practical. I usually recover an additional 2 to 4 quarts of wort that others would have thrown away with the grain. And no, I haven't tasted any nasty tannin bitterness from squeezing.