I found this top at Goodwill a couple months ago. I loved the lightweight cotton and the ruffles but it was a couple sizes too big and crying out for some color!
The top had a side zip, but I decided to turn it into a button-up. I cut straight up the center, between the ruffles, and applied lace to the inside like in the picture below. That gives the buttonholes a little more stability and covers the raw edges. I lapped the right side over the left and made buttonholes.
Then I removed the sleeves and sewed up the sides to fit. I had to reshape the sleeves a little to fit the new armholes, then I sewed them back on. Quick and easy!