Changing tank top straps?

Hi there! Long time occasional reader, first time poster. Hopefully someone can help me!

I have a gray spaghetti strap tank top that I got on the cheap for a costume. It fits and everything, but I had the idea to change the straps and the seam around the neck to a contrasting color of ribbon. Any idea how I could pull this off, without winging it and just wrapping the straps with the ribbon? Help!