Making curved parts from templates often requires re-tracing the template in a larger size. You may need to bandsaw a cutting board to rough shape before flush trimming it to a template. Or you want to trace off a curved table top to create a wood edging for it. Accurately reproducing the shape in a larger size is nearly impossible freehand, but a basic set of washers can make the task easy.
The three washers here are common hardware store items. The width of the rim of each is different, ranging from 1/8" to 3/8". Being round, they will roll smoothly along your template by simply drawing with a pencil. The wall of the washer maintains an even spacing between the pencil and template.
With a template set where needed on the stock, a clean, even line can be traced off in seconds so the parts can be rough cut. This is especially helpful if you want to cut out parts nested together on a single piece of stock, or orient your template to match the grain pattern. This process of offset tracing was very helpful in making the curved moldings for a set of antique doors I was rebuilding recently. I created templates of the openings, then used this process to trace off the curved edges of the moldings. With accurate templates, I was able to create molding that fit perfectly, even though the curves were irregular. So next time you need to trace out a rough cut, create odd shaped parts, or even scribe to a wall, a simple washer may be the key to improving your results.