I have made about 6 or 7 t-shirt quilts and am about to start another. As others have said it does get easier each time. I have a press that I use for putting the interfacing on. The first one I did I used a conventional iron. At that time I told my DH that if I ever made another one I would get a press - surface measures about
22". That makes putting the interfacing so much easier. I believe the fusible I use is either 911 or 913 from JoAnns. I cut off the sleeves, neck and sides of the t-shirt, then cut my interfacing rather large, press it onto the t-shirt and then cut it to 12 1/2" sq. A bit of waste with the interfacing, but I don't have to struggle with trying to fit the interfacing to an already cut shirt. If anyone wants me to confirm the interfacing type, just let me know and I will look it up tonight when I get home.