In the Print-On-Demand business model, there's no definitive list of the best products to sell. Having spent a couple of years in this line of business, I've sold a variety of items – from coffee mugs, phone cover, cushion cover and T-shirts to skirts, hoodies, curtains, doormats, mouse pads, shorts, flip flops, and stickers. Platforms like Redbubble offer around 80 product categories, while Printify extends to over 400 products. Your success in selling through Print On Demand model relies on your product design, SEO, and digital marketing skills. To enhance your reach, consider offering multiple product options with the same design and also in various colors, and sizes, catering to a broader audience.