We've seen some truly beautiful boards, both mass produced and custom made. Two of the most interesting were a round one (which I'm partial to; made by Third Eye Productions) and a blue triangular shaped board. A good way to create a rough design is to write letters, numbers, and any symbols you wish to include on index cards, arrange them into various patterns and try them out first. This will help you design a good workable layout.
Inlays of different woods for the letters might be nice if the craftsman is able to do it and the cost is not prohibitive. Wood burning is frequently used and works well for smooth boards. When using burl or other costly figured woods such as bird's eye maple, wood burning should only be attempted by a pro.
If the cost is high, an interesting way to make it look like inlay is to start with a tight grained wood (like a smooth oak or maple which have some good magickal attributes) and coat it well with a stain primer (two coats). Then, cover the entire board with removable drafter's masking tape. This is available in many paint section of stores and at art or drafting stores. Make sure it is pressed down well so it is sealed tightly to the board.
Now, develop stencils of stylized letters and numbers, plus any decorative designs you wish to add (such as a protective pentacle or some creative scroll work or Celtic knot-work).
Trace the stencils on to the masking tape and carefully cut them out with an Exacto® knife or razor blade (keep the blade sharp by replacing it frequently so there are no tears or snags in the tape). Practice first, it is okay if the wood gets cut a little, but not more than about 1mm into the wood. Cutting into the wood just a little helps to create a sharper edge and overall inlay effect. Cutting too far will make the board appear 'cheap' and could weaken it and prevent the planchette (pointer) from moving freely.
Now, peel off the cut out areas (like the letters & numbers) carefully and using a soft rag, dab more stain sealer over the entire board. This final coating of stain sealer over the entire board will fill in the tiny crevasses between the wood and the tape, keeping your lines crisp. Allow this coating to dry or cure according to the instructions on the can.
Next, lightly dab a darker stain onto the exposed wood to stain the letters and stencils you cut out. You may also use any color of paint if you are not trying for an inlay effect.
There are several shades and hues of stain that will work well, from red maples to medium walnuts. Dark oak stains are also nice and diluted liquid Rit® dye also works. Dye creates a light tint that is fascinating, but this takes more practice and bleeds under the tape more easily -which fuzzes the lines and looks bad). Allow stain to soak in and then wipe up any excess or shiny areas.
Finally, let it dry very well, read the stain can and allow the maximum time. Once it is completely dry or cured, peel off the remaining tape. If there is adhesive residue, use a very fine steel wool to gently buff it off.
Select a varnish that creates a hard smooth finish. I'm partial to teak oil, and boat varnish or 'liquid plastic skating ring and basketball court varnish' work quite well. But then, I'm rough on stuff and tend to work outdoors. Many people prefer to lightly wax the board, finish it with tung oil, danish hand rubbing oil, or to use a satin finish polyurethane.
Think about how often you will use the board, and where or how it will be stored, then look at the hardware store for your options (or ask for assistance from a clerk). Follow the directions on the product and coat the entire board well. The unstained sections will darken slightly from the finish, so it usually isn't necessary to stain the rest of it.
For this technique, we recommend a varnish type finish and not an oil type finish (unless you are building layers with teak oil). Some oils will not protect the stained sections well enough and may make them bleed. If you will be using the board in darkened or candle lit rooms, use a satin finish. A gloss finish will reflect and glare, making the messages difficult to read in low light.
If you notice any 'bleeding' or hairline marks from the darker varnish invading the background wood, remove them as much as possible using steel wool but don't overdo it. The stain primer should prevent this.
If you still have some bleeding, use a varnish that has a light stain in it. Minwax® makes one that works well. Select a very light version of the darker color you used. For example if your designs were dark oak, use light oak. If they were deep maple, try light honey.
After each coat with these stain/varnish combinations, make sure that you aren't obscuring the designs by making the entire board too dark. If it is the right color, but not varnished enough, use a clear varnish of the same brand and type (same chemical bases) to complete the finish. Even if your lines aren't bleeding, this technique of using a stain/varnish combination top coat gives the board an aged and blended effect that is interesting.
You may wish to create the board or commission it to be made during the waxing moon, and focus on its purpose and your goals for its use the entire time you make it or it is being made.
Good luck and have fun!