I used the how-to found here, and used the bias tape as casing for the elastic on the sides. But first I drew the pig snout onto the fabric with crayon and ironed it between layers of paper to set it.

Also, the bias tape I used was leftovers from another project and I didn't have enough to make the ends long enough to tie, so I just attached them so they held around the back of the ear.
Turns out that was an excellent decision - didn't have to worry about messing up my hair!
I was very pleased w/ how this turned out - and it was a big hit.