I use single fold binding in table toppers and stuff that won't get hard use like wall quilts. I cut mine 1 1/4" wide as it is easier for me. Some folk prefer 1 1/8" but that is way to small for me.
I use double fold for quilts and things that will get lots of use. I cut this 2 1/2" wide. Again, some prefer 2 1/4" but that is way to small for me.
ali