Ear cuffs aren't your typical peice of jewelry. To wear them, you push the 'hook' part over your earlobe and then slide it into place. Once the ear cuff is on, you can gently adjust it by pinching or pulling the part that wraps around your ear. The wire will not stand up to repeated bending, so adjust it once and leave it. (in other words: Do NOT open and close the ear cuff every time you take it on or off. Slide it over your ear.)
This is how they are worn:
The design of this particular one allows you to wear earrings, too.
And a picture of another one I made, so you can see its shape: