I use Stabil in the gas tank. Usually change the
oil in the fall or early spring time.
I start up the car at least once a month and let it run till everything gets up to temp. If there is no snow on the ground and the streets are dry - I put on a wool hat, gloves and go for a ride.
Start it at least once a month. I start my snowblower once a month in the spring/summer/fall. Its an 8 HP Arien's and it starts on the first pull every time ... oh, I almost forgot - it's 20 years old.
If you really want to get serious, they make plastic spark plugs filled with a dessicant. Leave them in for a month, then put them in oven for 30 minutes at 250 to dry them out ... and re-install. I have an old set I use with my non-Cobra toy (70 Olds 442).