If you want a good mule deer buck in velvet, I would consider packing into GMU 244; someplace like Buck Creek Pass, Chiwawa Basin, Spider Meadows or the Entiat Meadows. Hunt the first week of September. There are probably some good spots on the north side of Lake Chelan and north of Winthrop as well. You can also shoot a doe at most any of the trailheads.
Obviously, you should put in for the late season tags.