I'm planning to make two of these for myself, one for everyday, and another more for public use.
I found a tutorial online on BlissTree and successfully followed it. I think the hardest part was sewing the boning piece in, but I managed, albeit slightly crooked lines--but hey, for a first project, it's not too bad!
(And yup, that's a self-made crocheted boobie beanie on the printer)
I used a single sheet of snuggle flannel purchased from Jo-Ann's.