Bias binding for me. All finished cutting, piecing, starched and folded for my project. It's wrapped around an empty coconut oil jar that has straight sides.
Off topic excitement:
Also started my first attempt at free motion quilting and oh my gosh! Started with wavy lines and it is so intuitive, it just flows. I had no idea; I'd been dreading this for so long for fear that I'd flub it up.
As to why I do bias; I think it is easier to work with. The bias gives when needed, and I don't get that rumple that starts happening with a straight grain piece when its wrapped to the back.
Another thing; I wonder if anyone else does this but I sit down and graph out the placement of the binding around the quilt, showing where the seams fall before piecing the binding together. That way no seams fall on a corner.