Just finished a t-shirt quilt for a friend's daughter...LOTS of size differences (several sizes of shirts!!)...so I used some smaller designs from the front of the shirt (the ones on the left side-small logo, etc), and put them together with sashing, and added to the smaller designs.. The daughter is thrilled...that I got more than the "big designs" incorporated...some blocks have "sashings" to make them the right size, before the "real sashing" gets added...I have done them by adding a coordinating color for the smaller design to make the block as large as your largest block before sashing...