After looking at the posts on this thread, I am not happy with most of the solutions. I believe that except for temporary patches that can be hung from a pocket flap, all other patches should be properly sewn on. All pockets should be functional. Patches need to be replaceable. If you can find a very small curved needle, it would help considerably. Do not throw away replaced patches, save them for your boy or girl.
1. Slip something in pockets so you don't sew through to the uniform underneath.
2. Pin the patch in place and measure for accurate placement.
3. The stitching I most often