Stunning much?

I was in Diva the other day filling in time while mum and my aunty were having a coffee and I found some really gorgeous neck pieces, which inspired me to start designing one for myself, seeing as I am ment to be saving money :P I don't really know where I am gonna start but I was on the Sportsgirl sight and found these gorgeous embellished pieces.

Any ideas on how I should make one, what I should make it out of and what it should look like would be awesome!