Backstory: Those dog socks seemed to be the number one adult gift this year. Everyone at the office was showing off their custom dog socks the first day back after Christmas.
The Idea: A custom pattern printed pen.
Deep Dive: Similar to the dog socks website, you would allow users to upload an image and preview what the product would look like. Once the user places the order, you would print and fulfill the pens.
Validation: This whole idea was based off the dog sock craze. You could try to find a local printer to print a few orders for you before you spend money on a commercial printer.
Monetization: This is a straight ecommerce play, you would charge for your product, just watch your margins!