I get so many requests to customize a cake for someone special, but they don't have an idea what they'd like. I always ask them to describe the person, their hobbies, profession and whatever you can think of.
Sometimes we end up deciding on one theme and sometimes we can decide on more than one. An easy way to blend different hobbies is a stack of books.
For this client, the birthday boy was turning 70, he was an Actuary, loved hockey and also wines of France. He also loved Tom Petty, so I made a sugar version of the Greatest Hits CD which is not in the picture because it was still drying when I took the photo.