Just do really fast, sloppy dissesections (go through the motions, don't worry about throwing the baby out with the baby fat) and then spend the time you saved studying netters/whatever else you use. Then later, when everyone else is done w/ lab, go back in and study other peoples dissections.
I'm serious--don't listen to anyone who says you need to be able to find stuff in your own cadaver, they just want you to suffer. I spent only the required time in lab (which I spent goofing off mostly) and was one of the top students in my class. If you know landmarks and can tell the difference between a nerve and an artery you'll do fine as long as you know the anatomy.