You could certainly light up your "LOL" design with a flickering traditional candle. (If you do, we like your sense of irony!) But for shining, cell-phoneworthy illumination, buy the brightest LED light available. As a bonus, lighting your pumpkin with a modern battery-operated candle means no smoke to corral and no relighting when the wind blows.
1. Fasten your printed LOL stencil pattern to the side of your cleaned-out pumpkin. Mark the design onto the pumpkin's exterior by piercing along the stencil lines with a needle tool, creating tightly spaced holes. Tear off the pattern after outlining the entire design.
2. Cut out the design with a sharp, serrated crafts knife. (Hint: For best results, cut out sections from the center of the design first and work your way outward. Keep cutout sections in place until you've finished carving the entire design.)
3. Push on cutout sections from inside your pumpkin to nudge them out. If any sections are stuck, run your knife around the edges to ensure they've been cut completely free from the pumpkin.
4. Light up your LOL design by placing a battery-operated candle inside the pumpkin.