There are about a zillion ways to get color , design, etc. on wood. Go with what the other fellas said, use artist acrylic paints (watered down to a "wash", Dana uses stain and wadded up cloth (I think) his bows are very nice. About the only thing new I could tell you about is using different color stains and do it like you would Easter-Eggs for the kids........Start with your lightest color and when dried....use a crayon to mark out some designs...then apply the next darker color....more designs....more color etc. etc. just like coloring the eggs
Wipe the crayon off at the very end.
Another thing I havent seen listed yet is to use stain and (while it is still wet) take a rag with the appropriate thinner and blot, rub, wipe etc. to produce a number of different effects.
Hope it helps a little, but like nugget said just practice a little on some scrap wood first.
half eye