What do you use to winterize?

Marvel Mystery oil in the gas tank and oil? Does anyone use seafoam? Which is better to winterize your prized possession? Also I hear many things people use to keep mice away. Peppermint oil? Bounce dryer sheets? Moth balls? This will be the first winter for my car with its newly upholstered seats and new rug.
It would be best to have it in a building that is rodent proof. I dont fall into all of that "putting it on jack stands bit" ethenol free gas will last through the winter. At least mine does.