I use double-folded bias (I cut my own) and I press it in half. It's much easier to control as you pin it to your quilt. I use empty paper towel holders/toilet tissue empty rolls (a tip I got off a post on the QB!) and unroll it as I pin it to the quilt. And, it doesn't seem to stretch even though it's cut on the bias! Just MHO!
Jeanette Frantz