As you know marking wood with a pencil has it's drawbacks particularly when using a heavily grained wood like oak or a dark wood like walnut. The pencil mark is difficult to see at best. A few years ago I discovered day-glow orange masking tape. This tape catches you eye and is great for numbering pieces and or indicating a pencil mark for cutting.
While pretty expensive I seldom use long lengths and a roll will typically lase a year when I am busy. About $8 per roll. About 3 months ago I had my wife pick up a roll at the hardware store and she could not believe that the stuff was $8 per roll! Back in December she assisted me with the airplane project which had countless track saw cuts on cobalt blue and brushed steel grey plastic laminate. Pencil marks are very difficult to see on those colors. She saw me use the orange tape to mark my cuts and she instantly agreed that the orange tale was worth every penny. She gave an extra roll of orange tape for Christmas. Woopee.