Help Black Widow's Bracelets

[edgarrve]

Hi, I would like to know if some has an idea of how to make Black Widow's Bracelets from Avengers Age of Ultron.
I'm focusing on the black top of these.

I'm making the black widow cosplay for my sister and we're missing these.

I don't know how to model in 3D software to make these on pepakura.

 

[Lord Magneto]

Take a piece of paper and sketch it out. Cut it out and track it to cardboard or styrene and cut it out and shape it etc.