Finish off your ring by tucking under the filed ends - you can use the flat-nosed pliers like you did in step 4 to do this. You can also use your pliers to tighten the "bellybutton" by lightly squeezing any arcs that need it - be careful not to scratch up the wire though... (and don't forget to mind your fingers around that pliers - especially with thicker wire because it will take more pressure to straighten the ring and curl under your wire ends)
The two wire loops of your ring may be slightly misaligned when you first take it off the mandrel - to fix this just pull slightly out on the appropriate sides of the two loops using your fingernails until the wires line up.
Well that's it - this is a great little ring and I couldn't make 'em fast enough back when I was actively selling in stores and art/craft shows. Please tweak and embellish the design at will and I don't mind if you sell what you make, just please don't sell the instructions as they've always been free.
Hope you like the instructable!
- You can also start your ring with only one wrap around the mandrel rather than two. I like two because it's more interesting and it allows slightly more room for the wire ends as they curl under the "bellybutton." You can also pull them out and flatten your completed ring to make a bracelet by linking them together. You should use a minimum wire size of 18 gauge for the bracelet though - the 20 is a little too yankable.