Two lines are better than one for cutting accurately
No matter how old or young, the first time we cut wood on the bandsaw, we learn to follow a single cutline, staying to one side of it. So it runs against our nature to accept that two parallel lines drawn on the workpiece are better than one. I'm not sure why shooting for the gap—1⁄16 " is plenty—between the lines is easier, but since I started using this technique, I rarely let the blade wander over the line as I saw. Ironically, by giving myself more room for error, I get even closer to the perfect curved cut. To create the two lines, I simply freehand a line parallel to the original cutline. Go ahead and try it; I'll bet it'll work for you, too.
—Warren Perkins, Millington, Mich.