Hi Bowfish and all!
The traditional method of tigerstriping a light-coloured wood stock or ramrod is to use a soft, fibrous string or strip of linen, soak it in tar or pitch (modern asphalt roofing tar works) thinned with paint thinner or turpentine, and wrap it around the wood while wet.
Set fire to it! Let it burn enough to give good colour and contrast to the wood, and then extinguish. Remove cloth or string. Sand the wood to give the colour and partially expose grain, and apply finish.
You can also use strong, BLACK tea or potassium permanganate to stain the wood, and selectively sand off parts like above. Apply finish to suit.
HTH
John