1-   Anchor large exterior items such as sheds, gas tanks and air conditioning units to the foundation of your home or to the ground to prevent them from becoming flying debris.

2-   Caulk and/or install weather stripping to all doors and windows to prevent wind from entering.

3-   Have cut-to-fit boards and mounting frames ready for all windows and doors.

4-  Apply a ¼ inch bead of wood adhesive (APA AFG-01 certified) along the intersection of the roof and deck AND roof support elements on both sides of the beam.  This can increase the wind uplift resistance of your home by up to three times more than nail-secured sheathing alone BUT should only be used on roofs one year or older.

Source:  Federal Alliance for Safe Homes