Be thoughtful in your souvenir purchases - and if so suited, look for wedding-themed keepsakes. I have always collected Christmas ornaments from my vacations, and we were able to pick up a bride and groom/Mickey and Minnie ornament, that for a small extra fee, we had personalized with our wedding date. I also snagged the "Mr. & Mrs." Mickey and Minnie picture frame, which we used to hold one of our favorite wedding photos.
My husband and I also sought out other, meaningful keepsakes to take home with us: a pair of crystal-and-pearl Mickey earrings. A lantern from the Morocco pavilion that we plan to use on our back patio. A piece of fine art from the Disney Gallery to hang in our home. (We also splurged on other, less practical souvenirs - like t-shirts, candy, and other assorted trinkets.)
One thing we did strive to do, and were only moderately successful at, was to limit the purchase of gifts for friends and family back home. We'd worked hard to save up for our honeymoon, and the intention was to treat ourselves. That said, we still came home with a few goodies for our nearest and dearest -- resisting the urge to spend on others was MUCH harder than we expected, but we knew it was important to make sure our honeymoon was about us.
Upon returning home, I'd recommend scrapbooking your trip as soon as possible. For one thing, the trip's details are still fresh in your mind. For another, it's a great way to fill your time now that you're home from the honeymoon, done planning a wedding, and facing a harsh return to the real world. (Plus, let's face it - your wedding photos won't be ready for a few more weeks, at least.) I used Shutterfly to create our photo book online, but you can either create a more elaborate, hand-crafted album - or simply slip photos into a pre-made photo book. Whatever suites you, put together your honeymoon photo album soon after returning to extend the magic a little bit longer. (If you are so inclined, Disney even sells scrapbooks and photo albums in their theme park gift shops.)