I’ve shown you pieces of what I have done on & with this shirt. Here comes it all.

The start, made the sleeves longer and wanted to add other cotton fabric in the between where the needles are on the put.
After some changes to make it look propper I had to find fabric that would work together not just with the cotton but both way’s. And here I’ve used the buttom part of a exercise top which the fabric is elastic and the bottom part is an old summer top with polyester fabric.

I needled it up with the inside out to make sure the folds on the cotton fabric turned out right. I haven’t used a pattern, just how I thought it would be easiest to do it.
Then I turned it inside in and the right side out. Took up all the needles one by one to get the fabric on the right side. The tricky part was fir sure the folds!

Sew the bottom piece on first and then the middle part.
Sorry for the background.

The very last part to do and sew is to make a band in the same fabric as the shirt and try to match the stripes 🤪 on the band with the shirt part. See next picture.