Unless you are in Florida or Hawaii, now is the time of the year when its beach season!! Sometimes you know when you are going to the beach, other times it may be a spontaneous thing. One suggestion I have to is to pre-pack a tote bag!
Fill a tote bag with towels, swimsuits/trunks, sunscreen, hats, bottled water, non-perishable snacks, whatever you think you would take to the beach. Store it in the trunk of your car, or neatly corner of your closet. Have fun and be safe!