One of the best parts of a trip is often the daydreaming, discussions and planning that precede it. Brainstorming ideas, doing the research and putting together your itinerary are all just as fun and relaxing -- for some, even moreso! -- than the trip itself. By keeping a checklist of mundane details as you go through your regular routine, you can be inspired in the weeks before your trip to remember all the little things that make your life easier.
While it's impossible to forget that your child has allergies or gets carsick, for example, just noting it somewhere means that when it's time to create your master lists, you'll include extra supplies for those not-quite-everyday complications. If your youngest wets the bed, remind yourself to bring extra clothes or wipes. Picky eaters? Keep a secret stash of healthy food in case they shut down completely. Anything that happens, all day long, can inspire a list item that will make things easier when it's time to fill the camper.
There's no shame in writing down even obvious things: You're bringing your family's entire life along with you, and everybody knows you can sometimes forget important stuff in that last-minute dash.