General tidy up - make sure all the loose items from summer, such as chairs, tables, planters, tools, etc are put away in a secure place. Winter weather can wreck these items, and winter storms can send them flying.
Clean up - make sure that food stuffs are either well packaged, stored somewhere else or thrown out. Mice love a winter meal! Putting linens, towels, dishcloths, etc somewhere extra dry will help keep mould from growing on damp fabrics.
Lock up - make sure the property is closed up properly. Windows and doors should be latched so wind doesn't blow them open and so that critters can't get in.
Docks - make sure the surface is "gripped" or cleaned so that if someone needs to use the docks they won't slip on the slick surface from all the winter moisture.
Trees, shrubs, etc - now is a good time to prune any dead branches or long branches that are getting too close to buildings. These can come down during winter storms doing a lot of damage with no one around to clean up. Better to deal with it now.
It's a Coastal Lifestyle ... Live It!