6 images on the left (masks) from strawberry lemonade, candied apples from mattbites.com, glitter pumpkins from apartment therapy, baby boo pumpkins from country living, canisters and trick or treat cards from casa sugar (halloween decorations found on etsy).
I feel like the key to any theme is subtle. I wanted alice in wonderland to be incorporated in our wedding, but subtly, and it manifested itself in the form of teapots. I've seen a lot of other really cute ideas as well, and you can definitely have a lot of details that correspond without screaming "I'm in a Disney movie, oh God!"
I think unless you are actually disguising your halloween party as a wedding, you should follow the same rules. Instead of orange and black, pick one of the two and let your other color be white. Instead of using halloween puns everywhere, pick an antique font and off white cards (like the trick or treat cards above) with black text.
The baby boo pumpkins are my new obsession, and I want them as my pets.
With glitter pumpkins you could add a fall hint to any color scheme and it will be glam!
Try an all black (or all orange) candy buffet (the image above is actually beans and lichens but I like the idea of placing cards in the candy vertically so that when the candy is taken a message appears! If you use a stand like restaurants do to display their specials, you wouldn't have to worry about it falling over or getting messy from melty candies. Just pop it in and pour the candy all around!)
Masks can add a great addition to a photobooth (they are not easy to breate in, though). Animal masks are pretty much always creepy and they also have a breakfast at tiffany's vibe. Let the dressing up be a part of the reception without having a bunch of zombies show up and drip fake blood all over your wedding.