There are lots of ways to make bias binding, but I find most of them to be inefficient, either wasting fabric or time. Marking and scissors? No thank you.
Anjeanette Klinder http://anjeanettek.com and I developed this fast, efficient and fun formula to make as much continuous bias binding as you need with only two seams, a long ruler, and a rotary cutter.
Download the FREE Magical Rainbow of Binding™️ at https://magic.geekybobbin.com/binding
The quilt behind me is Arctic Vortex https://geekybobbin.com/arcticvortex