I don't know what it is about sleeves this summer: they're everywhere in my mending/restyling pile. After much frustration with the progress on my County Fair entries (which must get done this week: aack!) I went back to the mending pile and put a new sleeve on an old blouse.
Blouse is a lovely textured coral silk. Sleeves were the same fabric, basic short sleeve. But the blouse had sat in the back of my closet for years, hardly ever worn because raising my arms caused gross bust gaposis. Should have taken a "before" picture, but I removed the sleeves months ago; I had actually worn the blouse once under a jacket with no sleeve at all.
Anyway, the removed sleeves served as a pattern basis. I slashed the pattern 3 times and added 2" of ease at the lower edge. Bought a matching stretchy lacy fabric to use for new sleeves. Tried it on, and decided the new sleeve looked "unfinished". So, instead of hemming it, I am adding a bias strip from fabric in the original sleeve (I made it bias so that the bottom edge would stretch a bit along with the lace; remembered to sew it on with a zigzag stitch for this purpose.)
The picture above is "in-progress". I wasn't at my ironing board to finish it. Will post "done" picture soon.