I do what's already been suggested. Ethanol is a problem, but worse for carbed machines. I've had good results filling the tank to the top, adding an ethanol treatment such as Startron plus some Stabil, then running the bike for about 10 mins to distribute through the system.
Agree with everything else: fresh oil, lube chain, keep battery charged.
As far as tires, it may be better to get them off the ground, but I've always just filled them up with air, a bit more than usual, and parked the bike on several layers of corrugated cardboard for insulation.