My son is tall and has long arms so most shirt sleeves are too short for him. He's attending a funeral next weekend and when he was home last weekend he tried on the only plain white shirt he has. The sleeves were quite short and he would have liked them showing out of the suit sleeve. So I suggested that I just add some material on to each sleeve. He wouldn't be taking his suit jacket off and no one would know.
I remembered that I had cut a sleeve off of another white shirt to make it into a short-sleeved shirt. I never finished it but I thought that I could use the sleeve material for the extension piece. Unfortunately the sleeves are different widths so I had to cut the suit shirt just above the sleeve placket to get the same width. Then came the problem of how to attach the lower edge to the new piece because they were different widths too. I decided to try the upper edge first to see if it worked before figuring out the lower one. I put the cuff piece inside the sleeve so I could sew the wrong sides together as I wanted to make a flat-felled seam. Then I pulled the cuff piece out so I could iron the new seam to have it easier to trim one of the edges before turning the other one over it.
I was trimming away when it hit me. Duh! Why not just use the the other cuff piece as the cuff piece for the suit shirt and I wouldn't have to fuss with getting the lower edges to match. I'll have to wait to see what my son says but other than switching the buttons if he wants, I don't see that it will matter. (Ok the shirt is flat-felled seamed and the cuff piece serged but who's going to peek in his jacket sleeve?) The sleeve is now 9 cm longer.
Next is trying to narrow the shirt. Sigh.