How would you attach an applique to a crocheted hat?

I have crocheted a green and white baby blanket and hat for my niece's son due March 17. I would like to attach a shamrock applique to the brim of the hat. I don't like the idea of hand sewing it for aesthetic reasons. I think that might look sloppy. In the past, I have hand sewed "Made by" labels on gifted blankets and was never happy with the appearance. Should I secure it with a few stitches from the back but then it would not lay flat on the project? Any ideas or suggestions that have worked for you? Thank you in advance.