I've had several people ask me about the collars we use for our freestyle routines. They are the easiest things to make, and only cost about $3 - $5 depending on the types of ribbons you use.
You can usually find the trims at any hobby or fabric store. For the bottom trims with the beads, these are sometimes found with the upholstery supplies. For the top trims, any flat ribbon will work - there are prints, sequin trims, and beaded ribbons that all work well.
Anyway - I put together a little how-to video in case anyone is interested in making their own.