A while back I was in Taos, NM, and bought a book for my friends Jen and Jim - "The Natural Paint Book" by Lynn Edwards and Julia Lawless. Jen is a big book collector in the 'how-to' genre, and I liked to book a lot. At the time I was residing in Moab near my friends, and picked that book semi-selfishly so that I could borrow me.
Unfortunately the move to Corvallis made dropping in for the book a little difficult, so we procured it via Amazon. The book is a great mix of theory and practical application, and covers all kinds of paints, waxes, and stains with beautiful photos and informative text.
There are a number of ways to make wood stain from natural elements. We chose beets and onion skins because they are in season right now - not to mention that we are longing for the reddish-orange hues of the desert.
Directions are very simple. Hot water + beet or onion skin = stain. To deepen the color we steeped the onion skins overnight. For the beets we boiled them and then ran the whole thing through the blender.
The plan is to put on layers of color, adjusting the total look by putting on either the onion skin or beet stain one at a time. We have black tea on standby in case we need to brown the whole thing up.