These are some of the beads I use. You can use any beads you want.
This is the craft wire you need. That piece below is the size you need to cut (about four or five inches).
Fold the end of the wire over about a centimeter ( the width of your pinky nail, from side to side not top to bottom, will do it, maybe even a tiny bit smaller) with the pliers. Now you can add beads.
Now would be the time to measure the ring around your finger. If you want the small beads (or whichever beads you are using) on the entire ring, then just measure and guesstimate. (see next step)
If you are planning on making a ring with a large bead or different bead in the center (see last step for pic) keep in mind that the center bead will be most likely be larger than the other beads.
This is about the size of the wire you need left when you cut the remainder off. About two centimeters, if you feel comfortable folding that amount of wire in half.
Fold the wire over with the pliers.
Fold the ring into a circle and tada! You have a ring! :)