When shopping for potential jack-o'-lanterns, choose a fresh but ripe (fully orange) pumpkin. The larger and smoother, the easier to carve.
For carving, boning and paring knives work best. Make sure they're sharp. Ice picks or a long nail are handy for scoring the surface or poking holes.
Spread newspaper over a flat, level work surface (this helps with cleanup). With a boning knife or other large knife, cut a circle around the stem big enough to fit your hand. Remove the pumpkin's "lid," then scoop out seeds and pulp. With a spoon, scrape out stringy insides. Wipe outside of pumpkin clean.
Create a face pattern on a piece of paper, then tape it to the pumpkin. Use the ice pick or nail to trace the pattern onto the pumpkin, scoring the skin. Or draw the "face" directly onto the pumpkin with a felt-tip pen. Then, carve out the sections with the paring knife.
Before inserting a candle, make a round indentation inside the pumpkin to help keep the candle upright after lighting. And, of course, always practice due diligence when lighted candles are involved.