How to make Quilted Coasters with Binding

I've been making some coasters lately and I'm totally addicted to them. They have a top and bottom layer and in between I have sandwiched cotton batting to absorb any spills and interfacing for support. The four layers are sewn together using freehand machine stitching.

Reverse side

The binding is turned out, and pinned to the back of the coaster with the raw edges folded in and the corners mitered again.