Whoops,sorry-too many Easter eggs!
I attach mine by pre-folding the strip,in half length wise and then folding the edges in to met the middle fold line(so that it resembles bias binding). Now press it flat so there are two narrow hem on each side.(Pressing out that centre fold,that was a guide)
Gently smooth the two short ends and sew together to create a loop.
Pin and sew the right side of the sleeve binding to the sleeve edge(use the fold line as sewing line)
Trim just a little bit off the seam and press the seam allowance towards the binding.(try not to press out the fold line)
Press the sleeve binding into the sleeve,roll the edge a little and finger press first if you need to.
Sew the hem in place,there should still be a folded hem of the inside.
When I stitch tiny sleeves I find it helpful to sew ”inside the tunnel”,sew the edge with your machine foot inside the sleeve with the top right way out.
I hope this helps,pop back if it doesn’t.
Happy Easter
Nicole