heat sun and ozone kill tires.
long periods sitting form flat spots.
get some tire covers ( I noticed in November alot of those darn election signs are being used to shade tires!)
when sitting for long periods, I use jackstands to relieve some of the weight from the tires and suspension
I have a big jack...I have jackstands already so no added cost.
or...just start it up and drive a few miles every couple of weeks- that will move the fluids around in your motor. I would suggest driving far enough to get the motor fully warmed to boil off any water from condensation
Mike