Lots of things, but to mention a few. Last season I really started paying attention to the wind. Miraculously, I saw more deer, imagine that if you would. I am going to continue my study of air currents in hilly terrain, for one.
Second, I have spent this off season learning maps. I am going to take that knowledge to the deer woods, and broaden my horizons in that aspect.
Third, I will be in stand during the mid day "lull". I had some errands to run one day early November last season, got down about 10:00, back in stand at noon, wasn't there 15 seconds and a 140 class 10 pt passed directly under my stand, with my bow still on the ground. I will not be leaving during mid day this year.