Draw a pattern into a piece of plywood. Cut out the shape using a jigsaw. Then, sand the template to create smooth contours. The silver band surrounding the bit in this example of a plunge router is a template guide. With a template guide and a fluted bit, bear on a router template and cut a piece below the template easily. Make both inside and outside cuts with the template guide. They come in different sizes to accommodate the size of the bit. There is a slight offset of about 1/16 inch when using a template guide, so remember to compensate for the difference.
Elevate the material you want to cut on two 2 by 4 inch boards, so as to not cut into the table when cutting into the wood. Use double-sided tape to stick the template onto the wood. Use enough tape to keep the template in place, but not so much that it will be difficult to remove the template from the project. Cut the inside of the template using a plunge router with a template guide and fluted bit. Cut clockwise when making an inside cut. Make any necessary touchups to the inside cut before going on to the outside cut. Cut around the outside of the template counter-clockwise.