If you've ever tried to draw a straight line down a length of dowel to mark hole locations, you know how difficult it is to hold a straightedge along a round surface. Not only is that tough, but dowels are rarely straight. Here's the solution.For a dowel 3/4" or larger, place it in the miter slot of your tablesaw. Push the dowel into the slot until it's straight, and then draw a straight line where the edge of the slot meets the dowel. For dowels smaller than 3/4", cut a small dado into a scrap board and use the same technique.—Thomas Luc, Laurel, Md.