I found this tutorial about a year ago and it really helped me.
http://www.moosequilts.com/BindingTutorialWeb.pdf
Before that, I was just making a mess of my binding. I did do a couple of practice runs on scraps before I tried it on an actual quilt and I did get it twisted a couple of times like she said can happen.
I also do double binding and I cut my strips at 2 1/2 inches.