Be sure batteries are sufficient to run bilge pumps throughout the storm. Put duct tape on windows and hatches. Insert plugs in engine ports. Strip Bimini tops, sails, life rings anything that could blow away. Disconnect shore power.
Close fuel valves, and cockpit seacocks.
If you can, put the boat in a garage. If you must leave the boat outside, remove outboard motors. Lash down the boat. Fill the boat one-third to halfway with water. Support the axle with blocks inside each wheel.