1. This is the back of a dress skirt, not yet attached to the bodice, you do that after. I cut an opening of desired length; 3 in" is usually big enough for my girls. The skirt is inside out. Open the placket cut flat as shown.2. The width of my plackets are 2", measure the length of the placket and cut a matching strip from your dress fabric.
3. Turn the skirt over on top of the placket, so right sides of the skirt and right sides of the placket can be pinned in place.
4. Take to the sewing machine and with matching dress thread, sew a seam allowance that will be able to catch the middle cut and secure it. Make sure your dress is laying FLAT and the cut will almost be even with the raw edge.
Do you see how it is pinned? I keep my left hand under the skirt to grab pins and top stitch this neatly with a matching cotton thread. It comes out much straighter than if I was sewing from the inside.
6. Your placket is finished! Wasn't that simple? We attached the bodice here, and all that we need to do is hem under the lining and slip stitch, then add our pretty pearl buttons.