Okay, so you're probably like the rest of us where we start building benchwork without a definite plan for where the track will go on the layout. Or maybe you have a track plan and want to see how it will work in something more closely approaching the model's full size. In some of the more common scales, you can use masking tape to quickly lay out your track plan and more easily locate potential trouble spots. In N scale, like this photo (from a layout tour during the 2007 Midwest Region convention in Muncie, Indiana) shows, the standard 1 inch size of masking tape is a close approximation to the width of the track; in HO, 2 inch tape will work well. Once you've got the tape down, you can even put some rolling stock on it to see how it fits and "operate" it by hand before you cut any track. You can also set out any structures that you've already built or create mockups to see how they will fit into the scene too.