When starting to ebonize a project try to begin with a dark-colored wood, such as rosewood. You can ebonize any wood, but a darker wood gets black more quickly.

Mix up a fairly concentrated black aniline dye. I like to use a water-based dye because it's the easiest to work with and the fastest to dry properly. But because you are putting water on the wood, you need to raise the grain first. To do this, moisten the surface of the wood, and then when it's dry, lightly sand off the grain where it has risen.

To dye the wood, mix three teaspoons of dye in a quart of hot water if you are using a powder based dye or follow the directions on the side panel of the liquid based dyes.

Brush a heavy coat on the wood and let it set for about two hours. Since the idea is to get the wood as dark as possible, don't bother to wipe off the excess. But beware that you will need to mask off any areas you do not want the dye to sink into such as the back of the neck. If the back of the neck is already coated in clear you can wipe off the excess drip with no problems.

In fact, you may want to apply a couple more coats. When it's dry, simply apply a finish. I usually use a water based lacquer but most people just use a polish which in the long run will not protect the board unless it is properly maintained.