The way i did it was to trim a 1.5 inch brush , removing an eight inch of bristles, skip an eighth, then trim again, repeating across the brush, so when your done you have little fingers of brush, like your fingers on your hand. this allows you to paint multiple stripes with each stroke, this was how lehman did it. Use a base stain of light brown leather dye, then paint stripes with dark brown stain, practice first!