Things You'll Need
Instructions
Clip or notch a curved seam allowance before you press it open. This will allow the seam to lie more smoothly.
Cut tiny slits into a seam allowance that curves outward. Make sure not to cut into the seam thread.
Cut tiny wedges out of a seam allowance that curves inward. Make sure not to cut into the seam thread.
Iron the seams open to lie flat.
See "How to Keep Raw Edges from Fraying."