Getting autographs is such a fun experience for children of all ages!
Bring a picture frame mat to the theme parks and have characters sign! The mats with a 2' border are my favorite because there is plenty of room for characters to sign.
Bring a white tee shirt and have characters sign this on the front and back! Be sure to use a fabric marker.
A Disney storybook is a great way to capture the memories of your vacation with character signatures. These make great presents for friends too! Just don't plan on toting around a heavy book all day. I recommend bringing a small storybook that is light weight :)
Pillowcases are my absolute favorite way to creatively capture signatures! I recommend having your child's pillow monogrammed with their name beforehand. Then bring bright fabric markers for each characters signature. Never use Sharpies on fabric as they will bleed in washing machine. Did you know if you are going on a Disney Cruise that you can actually bring your pillowcase to guest services when you board the boat and at the end of the cruise you will receive it back, signed by all of the princesses (or you can choose the classic characters). I would suggest sending the pillow case and fabric markers in a sealed baggie with a thank you note and perhaps some candy for the characters or a small tip.