Remember the hole I fixed in my Colette Albion? I found some photos which I took whilst I was fixing it, and thought they might be useful to anyone wishing to jazz up a boring sleeve head, or fix a hole. This technique would work anywhere on a garment if it was near a seam.
First of all unpick the nearby seam.
Stitch new piece of fabric over the top, inserting the tab in-between. (hopefully my photos will be more descriptive than my text!).
Flip the new piece up and give it a good press.
Trim the sleeve head to the same size/shape as the original underneath.
Re stitch the sleeve back in place……Easy!
T H I M B E R L I N A 
That works for me! Nothing like a “patch” that looks like it was supposed to be there from the very beginning!
I’m just so glad I made than snip! Just goes to show everything happens for a reason 😃