Simply pull open one end of these earring hoops and slide your beads on. Put the end back into place and clamp it shut with pliers. This will crimp it so the earring hoop can't be opened again. Make sure you're happy with your design before you do this.
Finally, hang the hoop from the bottom of an earring hook. Earring hooks sold separately.
Beads will need to have a large enough hole to slide over the corner. Also good for wire wrapping beads on. There's a hole at the top center so you can hang a bead in the middle of the rhombus too.