My daughter listed her 100 Favorite things and we printed them up on iron-on transfer paper and stuck it to her shirt.
Since you're doing 10 groups of 10, why don't you do one or two lists of her top ten favorite things, like Top Ten Favorite Foods or Top Ten Favorite things to play.
Then type them up on the computer, print them up on transfer paper (you can get it at Michael's or any craft store (probably even Target), and iron them on the front and back of her shirt. If you don't want to ruin a good shirt, you can also buy cheap t-shirts at Michael's just for the 100th day. I still have my daughter's and she loves it. It's kind of like a time capsule, too, because so many of her top 100 things are forgotten about now. LOL
Updated