You're going to read this and wonder why a tutorial is even needed. It's honestly that easy - which is my favorite kind of project.
All you need to start is a bangle bracelet. You can find cheap ones at garage sales, dollar stores, your friend's jewelry box - uh, I mean, your own jewelry box. I've also used this process to make a bracelet out of a leftover duct tape roll center. They're perfect chunky bangle sized.
Next you need some ribbon. I save ribbon like a creepy hoarder, so the first bracelet I made actually used ribbon left over from tying up a present. It was lime green with white polka dots - of course I saved it. You tape one end of the ribbon on the inside of the bracelet to hold it as a start point. I recommend wrapping the ribbon on a diagonal when you start instead of straight up and down when you move around. It flows more naturally and will make your life just a little easier.
Then you wrap. And wrap. And keep right on wrapping the ribbon around the bangle over and over until it's covered. My favorite way to tie it off is to put a little glue on the end and then use clear tape to hold it down while it dries. Then you can either leave the tape on or tear it off once the glue has dried securely. And that's it. You're done, and you have a fancy "new" piece of jewelry for people to get all excited about. Pretend it was totally your idea - after you've shared this with everyone you know. Experiment with different colors of bangles and ribbon. Using semi-transparent ribbon can make a really cool effect (check out the gold ribbon on black bangle above).