I got the tutorial from The Suburban Mom. This tutorial is perfect, and I can't think of anything noteworthy that I really did differently. One tiny adjustment was that I assembled the bow a little differently by wrapping the bow in the same ribbon and gluing it in place, rather than using ribbon to attach the entire bow to the headband. (You may be able to see the subtle difference in my picture compared to her's.) And the only other exception is that I also made tiny headbands for the newest little babies that were coming to the party. I found out the approximate size of the babies' heads, cut a piece of elastic accordingly, and used black felt to cover the elastic band. Then I glued the ears the same way I did the older kids' headbands.
Finally, for my own personalized touch, I used pink or red fabric paint to paint each kid's name on the ears. I tried my best to match the Disney font. And I made a few extra ones that were blank in case someone showed up that I wasn't expecting or in case an adult wanted one as well.
All of the guests enjoyed the headbands, from young to young-at-heart. My mom even insisted on having her own with "Nana" printed on the ear. Several adults took a blank one for them, and I even had a special request for some headbands for people who weren't even at the party. Two of my cousins had just returned from Disneyland weeks earlier. I was most worried they wouldn't appreciate the headbands, being the oldest kids at 7 & 9 years old. However, they were thrilled, saying that it was a reminder of their trip. They even helped model the headbands while I was still in the midst of production, helping me to ensure that everything was the right size for all ages.