has anyone tried using the Witch's Hat flower nail? I found it on Kitchen Krafts but not sure how to use it for witch's hat OR for making roses either.

I have never used it but I believe the "hat" takes place of the icing center of the rose so that you can pipe your petals on a more stable base. I have one but I do my roses on the plain old flower nail or a stick. Hope that helps.

It's not for making witches' hats. It's just for piping roses. Instead of making the icing cone shape out of icing and then piping on the petals you just start piping the petals. I've never used one though.