On both of these sites you can design your own custom products. I have used zazzle to create souvenirs for my readers who like my art. I thoroughly enjoy zazzle, I used to be on cafepress too, but I would say zazzle is a better choice.
I welcome you all to review both sites yourselves and determine which is your preference. If you are like me, a person of the creative variety, then use any opportunity you can to share your work. Cafepress and zazzle are excellent, pricewise I like both.
I think the zazzle community is more creative than cafepress.
Perhaps I may be biased since I am on zazzle, but that doesn’t mean I am trying to boycott cafepress or draw users away from them. If you are satisfied @ cafepress,by all means continue there, but zazzle gives you a wonderful alternative option.