Halloween
So let's just come out and say it. Jack o'lanterns are not your personal canvas. I'm not saying that you can't express yourself artistically how you like. Go ahead and reproduce Marilyn Monroe's silhouette in vivid colors if you want, and snort cocaine until your nose turns to snot. But please do not try to impose yourself on established customs.
Jack o'lanterns are a grotesque face carved through the skin of a pumpkin. Then you put a candle in the pumpkin, and it shines out through the holes. If you are doing that on Halloween, you are doing it right. On the other hand, if you are etching a design into the face of the pumpkin without ever breaking the skin (and I realize you can get a more detailed design that way) so that the light shines through like an Alfred the Great lantern, you are doing it wrong.
If you are cutting something into your pumpkin that is not a pumpkin-type face, you are also doing something wrong. No images, Halloween-themed or otherwise. No pleasant smiley faces either. Please just a spooky, teeth-missing Halloween pumpkin face.
As I say, you can do whatever you want by way of art, but this is not art. This is buying into a pre-existing cultural thing. If you carve a pumpkin for Halloween, you are saying "I think that this pumpkin carving thing is a good tradition. I want in." But Alex, you say, is there no room for ironic commentary on the Halloween traditon?
Of course there is, but it's a fine line between wanting to participate in the Halloween tradition but still be more clever than everyone else, and really clever mockery or deconstruction of it. Additionally, Halloween is a really big thing. Any genuinely clever idea you might have come up with? Ten people have already done it, 5 have done it better, and it's not clever enough to leave on your doorstep for a week and a half. Get a new big creative plan.
Incidentally, all of this applies to Halloween costumes too. And if all of my rude remarks have led you to conclude that you can't have a jack o'lantern that pleases you and me, that's good too. Jack o'lanterns, like snowmen, are never as good as they look in the illustration. I'm not so sure we wouldn't be better off without any at all.