My girls (7 and 9 at the time of the trip) loved pressed pennies and pin trading!
I kept pennies in one zip lock bag and quarters in another. I counted my coins before we left and gave each kid a 'max'. I printed the list of where to find which designs and let them choose. I highlighted them so we knew when we were in a park with one of their chosen designs that we should grab that one

The pins, I bought ahead of time on
amazon. Much less expensive. I also told them that on the last day of our trip we would go to the Pin Store in Downtown Disney and they could pick any one pin they wanted

My oldest loved the Sorcerer's game in MK, you get the pack of cards for free so it is worth going even just for the pack of cards as a free souvenir.
Animation Academy in Hollywood Studios! They teach you how to draw a character and you keep your drawing from that day, on special Hollywood Studios paper

We ate so many sweets as it was in Disney that a cupcake a day may have just been too much sugar