Start by cutting a piece of twine about 20 inches long.

Fold it in half and tie a knot at the end.

Use a piece of thin wire to thread the beads over the folded end of the twine.

To do this bend your wire in half.

Slip one side through the looped twine.

Add your beads over both ends of the wire.

Pull them down until you hit the knot at the end.

Add as many beads for the length you wish.

Remove the wire.  

Add a few drops of essential oils to one or more of the beads.

Hang your wood diffuser onto a rearview mirror by placing the twine over the bar.

Open the loop with your fingers, and slide the beads through the loop.