Landowners- how about some habitat enhancement projects, for birds, providing nesting cover and winter cover are important. For deer, openings and food plots are important and it helps the turkeys, grouse and deer to seed trails in clover.
Dog owners- Start conditioning your dog early. If they are water dogs make sure that includes some water work. Young dogs can usually use a discipline refresher as well as hand signals and marking.
Archers- A fun summer night might include some field archery courses.
Of course there is always reconditioning equipment, repairing stands and hunting camps.
Before you know it days well be getting shorter and hunting season well be just around the corner.