I would use upholstery foam. There's a great place where I live where you can get a huge pad for 20 bucks as opposed to getting the same size from Joann's for $70. I wouldn't know how to do the feet, maybe heels? But your best bet would be to use upholstery foam.
Currently working on:
The Legend of Zelda: Ocarina of Time / Majora's Mask