Disney vacations aren't cheap, but that's even more of a reason to take advantage of all the free perks and experiences.
There are complimentary celebration buttons you can pick up from guest services or most merchandise locations if it's your first visit, a birthday, an anniversary, or a honeymoon.
I also like pin trading with park employees, where I can swap out any pins I have for something from their lanyards or boards.
For more interactive activities, you can also collect stickers and postcards around the world at Epcot with KidCot, sample international sodas from Club Cool in Epcot, get "pixie-dusted" in Magic Kingdom, go on a Pirate's Adventure in Magic Kingdom, become a Sorcerer of the Magic Kingdom, or become a Wilderness Explorer in Animal Kingdom.
You can also collect stickers and character autographs across the property.