I will add mine that we got the kids some 'souvenirs' before our trip, I gave those as presents in luggage and that is how we revealed the surprise. They each got 2 character shirts, a personalized Disney sweater, autograph book, pins/lanyard, and a guide book.
The Disney stuff was most of their Christmas present, they actually got the gift cards for souvenirs from their grandparents (who we told about the trip before the kids and we asked that they do gift cards for Christmas). I believe other than the Disney stuff all we gave them was 1 toy, a few books each and a few Disney movies to share amongst the kids.