These things typically come with heavy, bulky, fake gems, but fortunately, they're really easy to make with any bead you have. Examining these I discovered two things--one is that they are secretly just tiny sew-on snaps with fake gems glued on, and two is that they stay in hair really well without weighing it down, so much so that several can be clipped on the wave of a spiral curl of hair.
Step 1: Materials
Black ones will be less likely to be seen behind your bead, especially if you have dark hair, however you can paint them any color. It is up to you if you want to try to conceal the functional snap, but even if you don't, it is a small metal circle and not unattractive if seen behind a decorative bead.
They are very affordable at around a dollar for a dozen or better at sewing stores, and you can also scavenge them from garbage clothing items, although that might take a while.
Beads-- These should be the same size or larger than the diameter of your ball and socket snaps. They should have a hole through the middle, unless you plan to crazy-glue them to your snaps.
Superglue OR wire OR stringing material-- If you use string, try to use something that's not stretchy at all.
Step 2: Attach Your Bead to Your "male" Snap on the Flat Side
Actually, you could just as easily tie your bead to the female side, the only difference is that the female side is wider, and is not as flat where the nub is received.
There are four holes in the snap, and probably one hole in your bead. The only wrong way to do it is to have your bead over the nub, rendering your snap unsnappable.
In general, I try to tie square knots for their strength, but I try to tie knots only on the flat side so that they don't interfere with the snap, although they won't much either way. I also try to use the four holes in the snap. There are probably many good ways to do this, this is what I do:
To put a bead on, I cut some fishline and put either end into two of the sew-on holes, such that they come out on the flat side, then I tie a square knot before threading the two ends through my bead.
After the lines are through the bead, I separate them and put them through the other holes, then bring them together for a square knot between the bead and the snap.
Of course if you don't want to do all that you can just as easily crazy glue it all together, particularly if your bead has no hole.
Step 3: Test It Without Trying to Break It.
What you want to test for is how well your bead will stay on the snap during ordinary snapping and unsnapping actions.
You might accidentally put your thumb nail between the snap and the bead when trying to unsnap it, so pulling at the bead with a reasonable unsnapping action is a good test.
Step 4: Stick It in Your Hair
Clip your creation over a lock of hair and it should stay in quite nicely. If there's not enough hair in it, it may slide down over the course of a day. If there is enough hair in it, it may pull hair out if you try to pull it off without unsnapping it.
Well, that's all I know about these right now, if I figure anything else out, it'll be here, thanks for reading!