Gotta store my Fuchs and Bridgestones. Probably can do it in my closet if the wife doesn't find out.

What's the best method of prep and sealing them up?

 

I store the tires/wheels each wrapped in a plastic bag, stacked on their inner sidewalls. I can't say for sure that's the best way but it would appear to reduce deterioration of the rubber and prevent flat spotting the tires.

 

Keep them elevated off the floor if they are in a garage or somewhere that it can get damp. Keep the pressure up also. Do a search, I think this has been posted before.