If you're planning a day trip with your family, you're liable to bring either too much or too little stuff. No one wants to feel like they're reenacting the Western Expansion complete with a wagon train, but it's also incredibly frustrating to find yourself an hour or two along a trail without a diaper for the baby.

To help you avoid either of these extremes, here are some basic principles you should consider when you pack for a family day out.

- Clothing

Dress for the weather, but expect the unexpected. A sweatshirt is always useful if there's a chance the temperature may drop, and a hat is good protection from the sun. Most importantly, everybody needs a change of clothing, grown-ups included. Yes, it's probably going to be one of the kids that spills grape soda all over themselves, falls in a stream, or gets a bloody nose. However, the next stop on their trail of destruction is likely to be mom or dad and you may find yourself sharing in the grime, gore and goop.

- Food and drink

Dehydration is very unpleasant, so be sure to take sufficient water. If you'll be on a trail, away from a source of clean water, then you should be carrying a liter and a half of water per person.

If you're planning to eat out as part of the day's fun, then of course there's less need to take food with you. But it's still a good idea to carry some energy-filled snacks such as nuts, pretzels, fruit, etc. That way you can save your money for a couple of good meals, rather than constantly spending on spur of the moment snacks and treats.

- Clean-up, first aid, and baby supplies

If you're still in the diaper stage with one of your kids, over-pack on diapers and be sure to split them up between more than one backpack just in case you lose a bag, or get separated. Baby wipes, hand sanitizer, plastic bags and a couple of garbage bags will all allow you to keep things clean in any situation ... soiled or soaked clothes can be sealed up in a trash bag, while the debris of diaper changing can be carried easily to the closest trash can.

A small first-aid kit is a sensible addition to your backpack. Don't feel you have to be ready for every medical emergency, but some band-aids, antibiotic ointment, sunscreen and junior pain killers are useful to have.

- Toys and books

Whether in the car, at a restaurant waiting to be served, or taking a rest after a picnic lunch, you and your kids will be much happier with something to do. Even the most saint-like parent gets tired of the license-plate game eventually so be sure that everyone has a book, a favorite toy or game, or some crayons and a coloring book to fill some down-time.

Planning ahead and packing carefully will make your day trip less stressful, and more fun.