I carve the pumpkin, and it looks good for about two days before withering.
Lightly bake it after carving maybe? (what temperature and how many minutes?)
Is there a way I can soak it in some preservative like formaldehyde without starting the Great Fire of London?
Just this year I learnt you should carve out the top (stem) part. Apparently there’s some nutrients/water, magic, or something, left in it; and if you leave it uncut it will help the rest of the pumpkin look better for longer.
Cut out the bottom, or a hole in the back, instead.