I used the knitted in top-down set-in sleeve technique. The third picture shows a close up of it. If you are unclear how to do this easy and foolproof sleeve, you can read my how-to blog post here: https://www.kristenrettig.com/2017/02/how-to-knit-set-in-...

Once you use it you’ll never go back to sewing in set-in sleeves.