Roof and Attic
Inspectors closely consider drainage and leaks from the roof and around the house, including gutters and downspouts. Be sure to fasten any loose gutters and attach downspout extenders to keep water flowing away from the house. Also check the seals around any vents, skylights, or other roof openings. They may have deteriorated over time, and you probably don't check them every month.
In the attic, an inspector is mainly looking for insulation and ventilation. Blow in some insulation and put in the gable vent you never got around to installing. The inspector will note both items, and energy-conscious buyers like the added benefits.