String them and hang them in a bathroom (one in which you shower) or outside. Moisture in the air (from showering or otherwise) will oxidize them.

And of course, that reminds me that one craftsperson used to patina their brass items by sticking it in their cats' litter boxes. Each cat's urine created a unique patina.

Hmmmm.........

See: http://www.copper.org/applications/architecture/arch_dhb/additional/finishes/weathering_chart.html

Interesting link, love the colors, hated the timeline.

Luann,
Get some liver of sulfur that is in its natural hard state from a jewelry supply house. Just put a few pieces in a lidded plastic container and place your beads in the container it should oxidize your beads in a day or two.

You should put the liver of sulfur pieces is a small container so the beads do not make direct contact all that you need is the small amount of gasses that are released to do what you want.

Hope this helps you out.

All my best ....... Danny

Luann, the suggestion of putting your beads in a plastic bag with a small piece of liver of sulphur is a good one, if you want more control, here's what I do: Put the beads on a skewer, dilute the liver of sulphur in hot water, or if you're using the gel, you'll be using it straight. Work in the sink with a paint brush and the hot water running. Paint some of the solution on the beads (or you can do it one-by-one, my preference), then put the bead under the hot water right away. Repeat until you like what you see. This method keeps the liver of sulphur from developing its color too quickly and you should get more interesting shades. If you don't like what has developed and want to strip it completely away, you can use Tarnex for that. If you want to reduce the patina just a little, use a soft, brass brush and a liquid dish detergent. Seal with Renaissance Wax.

Another nice patina you can get is by hanging the beads over 1/8" of ammonia in a closed container. I poke a metal rod through a rectangular plastic sandwich box - you can put the beads on the rod, pour some ammonia in the bottom of the box and close the lid. The ammonia atmosphere will create a green patina over night. This I would seal with a matte acrylic medium to make sure it stays on.
Cheers!
Kate

(sigh) Just lost the entire post, trying again....

So I started with bright copper beads (upper right hand corner, the little rondelles), which are way too bright for the 'ancient and well-worn' aesthetic for most of my work.

The long oval beads in the lower left corner I soaked for a few seconds in a liver of sulphur gel (a drop in a container of water.) It all turned black almost instantly. It was hard to sand off, so I used a JAX solution for cleaning copper and brass beads, restoring it back to bright copper. Next, I tried a JAX browning solution. Though not as dark as the liver of sulphur gel, it was still too dark (and consistent in tone.) I tried to heat the beads--some of the brown patina came off, but not much. So then I sanded them to this finish. I like it, though I don't think it 'reads' as copper.

Then I did the smaller oval beads in the lower right corner. I just used the JAX browning solution, skipping the liver of sulphur step. Then heated them, and sanded them.

Last, I tried the suggestion someone sent me, using a very small amount of JAX and more water. This slowed down the process considerably, though I still had a satisfying shade within a few minutes. I haven't heated these nor sanded them. I think they might work!

Next time, I'm going to try the JAX green patina solution. But not on the 2mm copper beads! Too many, too small--maybe I'll order more of the bigger copper beads and go from there.

Thanks again to everyone who made suggestions!!

These are some copper beads I bought recently, already 'aged'. I love this finish and wish I knew how to recreate it!

Luann,
Rather than sanding buy some 0000 steel wool and then very lightly rub the surface of the beads, this will give you an "old look". I do this on all of my "Old Style" silver work and it works quite well.

All my best ....... Danny