Fold up the shirt collar and cut it off with scissors, leaving the neck band in place.
Pin 1-inch-wide ruffled trim around the neck band. Turn in 1/2 inch on each end of the trim to create a finished edge.
Pin the 1-inch trim around the cuffs in the same way.
Cut the 2-inch ruffled trim in half. Fold down 1/2 inch on the end of both pieces of trim. Fold one so that the raw edge is on the back when the ruffle is on the right side and the other so that the raw edge is on the back when the ruffle is on the left side. Sew 1/4 inch from the fold to hold the fold in place. Zigzag the other end of the trim to prevent unraveling.
Unbutton the shirt and pin the pieces of the large, ruffled trim down the front of the shirt, on each side of the placket. The ruffled edges should point toward the sleeves and the folded down raw edges should be hidden on the back of the trim at the top of the placket.
Sew along both sides of the straight part of the trim to the blouse, removing the pins as you go.