I have a collection of Testor's bottle paints in various shades of tans and browns. Ibrush a coat of flat tan and let it dry. Then I'll open 2 or 3 bottles of wood, dark brown, and cream and get out a fine brush. I kinda sorta make lines and a dipple (knot) here and there andd blend the colors together. Yeah, I know, not the greatest directions. Just get some tans & browns and play on some scrap pieces.