|Patch pockets with rounded edges are a staple in toddlers' clothes, but the pattern instructions usually leave much to be desired. Usually, they want you to iron under the raw edges. I don't know about you, but I find that impossible to do neatly. Usually, there are flat places in the results instead of a nice curve. I've been doing lots of them lately and I think I've hit upon a better way.
First, fold over the top edge, fold the raw edge under, and top stitch it. You should have the straight edge finished now. Starting 1/2 to 1/4 inch above the curve, run gathering stitches to the other side of the pocket. Loosely gather so that the curved edges are nicely turned under. Position the pocket at the desired place and pin down the top at the middle.
Now, fold under the sides and pin in place. Repeat with the rest of the pocket, making sure that there are no visible gathers. Topstitch in place around the curved edge. Make sure that not only have you locked the beginning and ending stitches in place, but that you've reinforced it, as that is the most likely place for it to come apart. Remove the pins and you've successfully installed the pocket.
I've done it this way several times now and the result is the same every time--perfect curved patch pockets.