after you've stained the base color you might try using a gel stain (combination product with poly) in a dark walnut or ebony stain. This is a wipe on product, so you can apply on the entire surface, then immediately start wiping off on the "high" areas (you might need some scrubbing action) with some lint-free 100% "cheese cloth" (you'll find in the stain area of your hardware/paint store). Stop wiping when you've removed enough of the darker gel stain from the areas you want to remain "light" and leave in the grooves and crevices and outer edges. Let it dry completely for a few EXTRA days, then coat with a compatible clear poly (sanding it lightly with 0000 steel wool just before for adhesion "bite"), consider at least two coats of clear poly for a long lasting top finish. Matte or gloss finishes are available.