Using a cunning combination of elastic and beads you too can crochet glamorous rings just like this one:

although it is not obvious in that picture, the beads are those white-iridescent ones, so it catches the light quite fetchingly and draws lingering stares from attractive strangers.
And now, here it is, the Amazing Crochet Bling Bling Tutorial.....
This is a pretty simple project, a bit fiddly. It uses crab stitch (also called reverse single crochet), which is where you put the hook in from the back instead of the front when you work a single crochet. You can find out about crab stitch here:
http://crochet.about.com/library/weekly/aa112997.htmTo make a ring you will need some elastic thread (like the kind on your underwear), some beads in whatever colours and sizes you like (I use the little seed beads and some slightly bigger ones every now and then for effect; you can use faceted or smooth beads), and a hook. I used a No. 1 steel hook (2.75mm).

Before you start, you need to string however many beads you want to use onto the elastic. So you need to figure out how wide you want the ring to be, and how long you want the beaded part to be. I was running out of my little beads, so I made a thin ring, only three stitches wide. I did eight rows of beads, so I strung 24 beads onto the elastic (3 x 8 = 24).

Now, make a chain, adding a 4 chain turning chain. Turn and work a treble crochet (tch) in the fifth chain from the hook. Work tch in each chain until the end. Work 2 more rows of tch.

As you can see, it doesn't look very neat. This is okay because you won't see the underside of the ring when it's on your finger (unless you turn your hand over). You will find, when working the elastic, that is is stretchy. wow. Don't pull it really tight, but do stretch it a little as you go. If it is too tight it will be a tight mass and hard to find the stitches, if it is too loose it won't have much stretch. Let it move through your fingers pretty easily.
Here is a warning: there are web resources for crocheting with beads, and they might be better than my description.
The first thing you need to do is move the first bead toward the hook and make a ch-1 turning chain, 'trapping' the bead in the chain. Then to work the first row, basically, I move a bead over to the hook before I start a single crochet, then I yarn over, so that the bead is in the loop. Then I finish the stitch, hence 'trapping' the bead on the other side of the crochet. Here's some pictures:

move the bead over

yarn over hook

ready to finish off the stitch

where'd the bead go? (it's 'trapped' on the other side, duh.)
When you've finished the first row of beads, made another turning chain, then work the next row in crab stitch. You do this because inserting the hook from the 'back' of the crochet means that the bead is trapped on the side of the crochet closest to you. If you just work each row in single crochet then the beads would be on alternate sides, instead of the same side.
Here it is halfway through:

When you've worked the beads into the crochet, make your next turning chain a 4-ch, then turn and work the row in treble crochet.

Now, wrap the crochet around your finger. It will probably need 1-2 more rows so that it will comfortably fit on your finger without pinching or sagging. Work those rows like the last. Then, when it's the right length, hold the two ends together and single crochet them together. Bind off and cut the end of the elastic.

Ta-da.