My machine has hoops for 2 x 2, 4 x 4, 6 x 6, 5 x 7, and 7 x 12 so I can use almost any of them. My favorites by far are 5 x 7 and the 6 x 6 although I have probably used the 7 x 12 just about as much. Also, I prefer to purchase designs that come in multiple sizes as I usually have more than one project in mind for each design that I purchase.