We were in WDW on my DD's 13th bday. That morning, she had a manicure at our resort's (Beach Club) salon. We had a character dinner that evening, followed by an Illuminations Celebration Cruise that I had booked way in advance. The boat was decorated with a banner, balloons, etc.
I also preordered a birthday cake which was delivered to the boat prior to our departure from the dock. When the boat parked for Illuminations, the two CM on board brought out the cake & started singing Happy Birthday and the guests on the adjoining boat joined in. The cake was so huge that we shared with everyone on both boats.