I enjoyed creating the Temphis Runes fonts and Rune Guide so much that I was determined to have a cool set of "prop" runestones to use in my Grave of Heaven games. But the local new-age bookstores wouldn't be any help for that. Luckily, I discovered that making my own is fast, easy, and inexpensive. I made my set for about $5 in materials, and it took me a little over an hour (including baking time, which means runestones are a heck of a lot easier to make than rune fonts). Here's how you can do it, too:

Materials

You'll need all of the following to begin:

An ordinary home oven.
Glass or ceramic bakeware.
Three 2-ounce packages of Sculpey III brand polymer clay (or a comparable amount of any similar oven-hardened plastic clay) in at least two colors. For my set, I used two packets of Sculpey in Silver with a third packet in Pearl. If you've never used Sculpey before, never fear! All you do is mold it and bake it in your oven, and voila - instant thingamajig. Assuming you already own the oven, this will be the most expensive part of the materials (a two-ounce package of Sculpey goes for $1.50 or so).
A tool to press lines into the Sculpey to make glyphs. I made my own glyph-pressing tool from thick cardboard, courtesy of the U.S. Post Office (I keep a few Priority Mail shipping boxes around most of the time). I cut a rectangle an inch long, then trimmed two of the corners at odd angles to create lines of differing lengths. Pressing the glyph-lines is much better than scraping them out with a pointed object; it makes cleaner lines. The cardboard made a funny scalloping pattern inside the lines that I liked, but any method that suits you will do.
A tool to poke dots into the Sculpey. A pencil will probably do. I used an instant-read meat thermometer!

Method

Set aside about an hour. Have clean, dry hands and a good working surface ready.

Step One: Tear Sculpey into pebble-sized chunks, kneading as you go. Toss them all into a mix.

Step Two: Blend the pebbles back into a single, smooth mass of clay. Fold, stretch and knead as required to make the kind of marbling or mottling that looks good to you.

Step Three: Roll the clay into a rope of even thickness. Use a ruler (or whatever method works best for you) to divide it into an equal number of pieces. Keep the size of the pieces as uniform as possible (there are 26 Temphis Runes in all).

[Actual Size Rune Image] Step Four: Create your runestones! Shape each piece into an oblong or oval "stone," using your fingers to mold curves and contours. Keep the shapes varied for best results, just make sure that each stone is flat enough to have two distinct sides. Press the glyphs into each stone using your pressing and poking tools. Work directly on the glass/ceramic surface you'll be baking on to minimize damage from moving the stones around. You can lightly rub your own fingerprints off the surface of the clay once you're done pressing in each glyph.

Step Five: Bake according to package directions, adjusting with care to suit your oven's performance. I found that my runes took a good ten minutes longer to finish than the package suggested (including a 5-minute "cool-down" period where I left the runes in the oven but turned the oven power off), but every oven is different. Sculpey can burn, too, to be careful not to singe your stones!

Step Six: Cool the stones completely; you can leave them on the bakeware or spatula them out onto a cooling surface (I used a marble cutting board with a pattern so similar to my runestones they were almost camouflaged against it). Once they're cooled, the stones can be painted, sanded, coated with sealant, or anything else that wets your whistle. Then you can think about making a nice cloth bag to keep them in. Enjoy!