To use a jack-o-lantern stencil, tape the stencil to the pumpkin, and use a template wheel or transfer tool to poke through the stencil along its pattern. Remove the paper, and use a carving tool to carve the pumpkin along the dotted line
Start by preparing the pumpkin for carving, cutting out a rounded piece around the stem for the opening, and removing the guts. Choose a stencil, and cut away the excess paper before taping the design to the side of the pumpkin. Use a template wheel that comes with most carving kits to poke holes along the lines of the stencil, poking deep enough to make visible holes in the pumpkin. If you don't have a template wheel, use a nail, a wooden skewer or another sharp object. Remove the paper to carve along the dotted lines using a carving saw.
Another method of transferring a design from a template is to place a sheet of tracing paper between the pumpkin and stencil, taping them both in place. Run a ballpoint pen along the lines, and remove the paper to reveal the stenciled design. A third option is to scribble a pencil across the back of the paper to cover it with graphite. When you run a ballpoint pen along the design, it transfers the graphite to the pumpkin.