Before you store your boat:
Clean the hull, decks, cockpit, bilge, all compartments.
Drain fuel lines, pumps, carburetor and tanks or fill completely and add fuel stabilizer.
Unless stored outside, leave floorboards up, doors ajar, ports, skylights, hatches drawers, lockers partly open.
Carefully fit a well-made cover, provided with ventilation ports.
Check tire pressure on the trailer