Here’s a good video on the braided join. (It’s my favorite join because 1. there’s no spit involved 2. you can use it with any type of yarn – wool, cotton, etc.) She uses 3 inches of the braid. With nalbinding I can get away with 1-2 inches and I usually pull the middle yarn down into the braid. Then there’s no “top” tail that gets roughed up as you pull it through stitches.
(Source: https://www.youtube.com/)