Along with my Batman costume, I also made some related decorations for the house.
Pumpkins: I'm a big fan of glowing pumpkins, rather than fully cut-out pumpkins. My two pumpkins are based on posters from Batman Begins and The Dark Knight. To make the pumpkins, I first draw my design on the pumpkin with permanent marker. I decided for these pumpkins that what I drew would be the dark space, and everything else would glow. I then cut an outline (not too deep) around all the lines, and then chopped away just the top layer of pumpkin by digging towards those lines at an angle, to make a little V shaped trench outline around all the images. From there it is easy to extend the cut-out area.
Next I colored in (black) all the shapes I had drawn. This is not necessary, but it helps make the images stand out a bit more.
Finally, to make the pumpkins really glow, I scraped away at the pumpkin from the inside. To make the pumpkin glow, you have to cut out a lot, but not all, of the pumpkin surface. This is tricky to do from the outside, because you have to be careful around your image. From inside the pumpkin, however, you can just have at it with a big metal spoon, and easily get the pumpkin wall thin enough for the candles to shine through. If you want to be really fancy, you can scrape away more or less in different areas to vary how bright different sections are.