Flip the hoop over. Bring the string around to what is NOW the front, and tie a single knot.
And that's it. Really. All you do is flip the hoop, bring the strands up to the front, tie a single knot, flip the hoop again, tie another knot on the front.. etc, etc.
Pretty soon, you'll be all the way around the hoop earring and on the other side of the opening.
Just tie a double knot there and dab a bit of hot glue to secure the knot, if you want. Trim off the excess yarn.
I really like how it looks almost like a herring bone pattern. Or maybe more like a fish bone? In any case, I think those criss-crossy knots are pretty cool.
And here is the horrible "picture in the bathroom mirror because they're finished and see how cute they are on now?" photo.
You really must scoot on over to Mandy's place.