Pack plenty of healthy snacks for the trip, such as fruit, pretzels, granola bars, crackers and nuts, along with a few fun treats. Take sandwiches if you know you'll be driving for a long stretch in an area with limited dining options -- or simply to avoid the temptation of fast food. You could also pack a picnic lunch to enjoy at a roadside park. A trip to the grocery store can help you save money, too, because the costs of dining out can really add up.
A soft-sided cooler packed with water bottles and a few soft drinks will come in handy throughout your trip, and it won't take up too much space in your car. Simply refill with ice and drinks at your hotel or destination, and you're good for the return trip.