mom always used to say, when I was bored, "CLEAN YOUR ROOM"
that never worked for me, either, so I'll keep thinking.
I like the bowhunting, beekeeping, and aquaculture ideas. Tilapia can be raised in kiddie pools or stock tanks in the summer, need heat, so I've read.
Go ginseng hunting? Fall mushrooming? Scout out deer areas (I wouldn't have to go any farther than my garden). Some folks set up salt licks for deer, don't know how kosher that is in your area.
Build a tower and start your ham radio license.
Fix that electrical quirk in the house wiring that really has been annoying you.
Lubricate your vehicle's window mechanisms. That'll keep them from jamming in the winter, electric or manual.
Sharpen all your knives and tools.
...wait a minute, I'm starting just copying my to do list...