You’ve done the backpack bit. Now, your journeys take planning. Preparing for a trip was simple in our youth: Stuff a backpack with a few changes of clothes and some personal items and head out to a grand adventure. Now, though, we may be gluten-free, diabetic, a little lame, sleep-deprived and out-of-shape. At some point, the inequity of age hits us all. That doesn’t mean we stop having adventures. It just means that for most of us, preparing for them is different — and should be. Here are six tips to help you make the most of your next big trip: Pack as if your bags may get lost. After being stuck in Italy for three days without my bags, I learned to carry a change of clothes (and several sets of underwear) in my carry-on. My husband and I usually check two bags: each contains half my clothes and half his. This ensures we both have at least some of the clothes and toiletries we need, even if an airline loses our luggage. Bring the food you need. If you must limit your diet — or eat every few hours — it’s easy to pack food to supplement what’s available at your destination. Peanut butter, small applesauce cups, rice cakes, crackers and meal replacement bars are portable and may be life-savers on the road. My three-week trip to India included many days when I was unable to eat the food available. One of our travel companions was diabetic. We were glad we’d each brought portable snacks and vitamins. Shed clothing as you go. Lugging heavy bags up the stairs in European train stations taught me to pack lightly. I save undergarments, sneakers and clothing that are near the...