Draw the design for the sign on paper. Determine the purpose of the sign to get a better understanding of the size and shape. You also want to know where the sign will be placed. Placement also will help determine size and shape. Knowing the size and shape will help determine the size and type of text, as well as images or other elements to the sign.
Use the tape measure to find the width and height needed for the wood. Measure from the anticipated lowest point to the anticipated highest point to get the total height and from the widest end of each side to get the width; this ensures enough wood for the project. Cut the wood to size with the saw.
Use the carpenter's square or compass to draw the final edges onto the sign. The carpenter's square will help create straight lines at any angle; the compass will help create a circle or oval. Cut the final edges with the saw.
Lay the wooden sign flat on a work surface. Sand the side facing you and the edges around it. Turn the sign over to the unfinished side. Repeat the process to create a matte finish. Make sure to sand out rough spots to create an overall smooth surface on all sides. Rub down both sides with a damp rag to remove dust and sand.
Paint the sides of the sign with the painting sponge or spray painter to get the background coating even. Use white paint as this will allow any other color or element more visibility. Use acrylic paint because it dries faster.
Draw the letters, design and any outline material. Use the pencil, so you can adjust the lines as needed. Begin painting over the design by tracing over the pencil outline. This will keep the color inside the lines. Use stencils for more precise designing. Finish the painting with artist's paintbrushes. Allow the paint to dry.
Spray the polyurethane onto the surfaces of the sign. Apply up to three coats for best protection from the weather and aging. Allow each coat to dry before applying the next coat.