Check the battery and charging system.
If your battery is more than three years old, think about replacing it before it fails on a dark, lonely road. At minimum, make sure the connections are clean, tight and free of corrosion.
Check your tires for uneven or excessive wear and tread depth.
Have your wheels aligned and rotate the tires to prevent early wear.
Check the HVAC system to make sure your heater and ventilation is working properly.
Change the air filters while you’re at it.
Check the windshield wiper blades.
These should be replaced every six months, anyway, so might as well do it now. Fill up the windshield washer reservoir, too.