If you're using a real candle (rather than a flameless one) to light up Robert Pattinson's smile, you have one extra step to complete. You'll need to cut a hole in the back of the pumpkin to allow the candle's smoke to escape. If you've carved your pumpkin from the top, you could also simply leave the pumpkin's top lid off while the candle is burning.
1. Start by spray-painting your pumpkin black, and allow the paint to completely dry. Carve a circle in the bottom of your pumpkin, and scoop out all the pumpkin guts. Scrape the pumpkin pulp thinnest on the side you're intending to carve -- around 1" thickness is optimum.
2. Tape your printed pattern to the pumpkin's surface, and use a pushpin to pierce through the paper and into the pumpkin's skin, following the stencil lines. Keep pin holes tightly spaced, and remove the stencil when all lines have been transferred to the pumpkin. Keep the stencil nearby.
3. Look on the stencil to find sections surrounded by dotted lines; you'll etch these sections. To etch, use an etching power tool or a gouge to remove the pumpkin's surface skin. Be careful not to puncture the pumpkin wall; you should remove just the pumpkin's top layer.
4. Look on the stencil to find sections surrounded by solid lines; you'll carve these sections. Saw along the pin holes with a thin, serrated knife, gently cutting from point to point. For extra stability, allow carved sections to remain in place until you've finished cutting the design.
5. Push on the carved sections from inside the pumpkin to slide them outward and reveal the stencil design. Light the pumpkin with a battery-operated candle.