If your motorcycle has a center stand, use it for long term storage.
If you're not riding for several weeks and don't have a center stand, you may want to consider carefully propping up the bike using blocks. Don't do more harm than good by dropping your bike while attempting to prop it up! If done correctly, lifting your motorcycle will alleviate stress on the suspension and tires.
Inflate your tires to the maximum recommended pressure will maintain their shape, since cooling temperatures will make the pressurized air contract. If the ground might potentially freeze, try to keep the tires off the ground using wood blocks.
