Tee shirt quilt
 

Have a tee shirt quilt that was put together and bound, but was not quilted or tacked in the center.
What is the best way to proceed. Stitch in ditch, or tack each corner with thread, please help

Since it is already bound I would tack or tie in the corners. I would worry about it shifting when quilted.

I would start in the center and SID as best I could.

Since tshirts tend to stretch, I'd tie the corners too. However, if the tshirt has been stabilized with a iron-on type backing, it may be stable enough to actually stitch right on the tshirts. If the foot of the sewing machine pushes the fabric around, you'll have tie it. I have a foot that "bounces" up and down instead of pushing forward. Don't know if a walking foot would work well on tshirts.