To make this peacock costume, I took a blue dress and ordered some peacock feathers from EBay which was a lot cheaper than going to a local craft shop.
I then took a round flat piece of Styrofoam and, using the same fabric color as the dress, covered the Styrofoam and stuck the feathers in the top to make the tail. I then took some feathers and hot-glued them to the front of the dress.
I used Halloween crayon makeup to paint her eyes and she used a play headband wig for her hair. It was all fairly simple and inexpensive.