I like the #2 idea from Prism99. I, too, have cut into my mitered corner before. ONCE. I learned my lesson REAL QUICK.
I'm afraid if I trim first, that there will be to much shifting around of the layers. If the quilting had closer lines, it might be different. I've done that before and it wasn't an issue. But I'm afraid of shifting.
When I usually do binding, I sew the binding with a contrasting bobbin thread, so when I turn the binding to the back, I can see better that the binding is actually covering the bobbin threads. I then stitch-in-the-ditch on the top.
Any more ideas?
Thanks