For those of you who want to shoot pumpkins, I highly advise you check out after-Halloween to buy your pumpkins super cheap. There. That's my tip.

For those of you who want some tips on pumpkin carving, I have more to offer!

Selecting a Pumpkin
Pick a pumpkin with your design in mind.
Use white or green pumpkins for a change of looks. (They are harder to carve as they have tougher, thicker skins.)
Use a fake pumpkin for a keepsake pumpkin capable of more than one night of use, indoor/outdoor use, and to avoid rotting and seed messes.

Some Good Tools
Large knife
Wooden/Plastic spoon for scraping out seeds
Metal spoon for fine tuning cleaning
Detail knives for small precision cutting
Tooth picks
Plastic Pokers
Wood carving kits (found in craft stores)
Pumpkin carving kits (found at most stores in seasonal sections)

Cutting and Cleaning
Leave a notch at the top of your pumpkin for easy placement of the lid.
Cut at an angle to prevent the lid from falling in.
Cut seeds along the top and scrape the rest out with the wooden/plastic spoons. Use smaller metal spoons to clean out the rest.

Pattern Application
If you're using a detailed pattern, cut lines at each corner of the paper as well as between the corners.
Punch holes of design or trace with a pencil using a graphite tracing technique (shade the back of the pattern with a pencil and then trace over the design and it will imprint the design on your pumpkin.)

Cutting
Use large knives for large areas.
Use fine knives for detailed areas.
Use carving tools to expose pumpkin flesh, creating different shades of light.

Mistakes
Use toothpicks to tack accidents back into place or for support on sensitive areas.

Preservation
Spray finished pumpkin with Lysol.
Coat cut areas with Vaseline or petroleum jelly.

Tips
The closer you wait till Halloween to carve, the better.
Place candle on aluminum foil to prevent wax from dripping out.
Use battery operated faux tea candles from dollar stores or craft stores in holiday sections to prevent candle from being blown out in wind.
Use glow sticks from dollar stores for a spooky color lighting effect.
Place pumpkin on aluminum foil for easier removal (if it rots, you don't have to pick up a gross mess, just wrap it up and toss.)