This is by far my favorite way making sleeves. I learned using Wendy Bernard’s wonderful book “Custom Knits”. I highly recommend it. The patterns are beautiful, simple and classic and she has so much great information to help you modify and design your own patterns. I bought the book when I had a pattern I loved but I wanted to do my own sleeves. I think these sleeves look more professional too as the seam is also perfect.
Recently, I saw this link and I think it’s the same technique and really nicely explained for someone who might want to try it themselves.