I do a lot of tee shirt quilts for clients. Few suggestions: wash the tees before working with them, even if person says they are clean. I learned the hard way. I use a lightweight pellon fusible on the back. I use a chalk liner to draw the sewing lines on the tee shirt and make sure the fusible is beyond that. I don’t trim excess until sashing is on, find it helps to keep the edges of the tee stable. If you have questions along the way, don’t hesitate to reach out...happy to help you.