Existing hat that fits person's head correctly
Piece of paper
Lay the hat down on the piece of paper.
Trace around the hat, then extend the sides up to meet in a point (make it as pointed as you'd like).
Cut out two pieces the size of your template out of felt and sew them together on the sides.
Trim the hat so that it is like you want it to be, then turn it inside out.
© Jennifer Ofenstein (ofenjen)'s tutorial was taken with permission from sewhooked.org