With respect to Halloween weddings there are several different avenues you could take but the main thing with the Halloween wedding is the idea of dressing up in costumes and doing something really fun and out of the ordinary. My first thought for a Halloween wedding theme is an elegant Gothic Wedding which incorporates a semi spooky mood.
In creating an elegant, Gothic wedding one of the prevailing styles is to incorporate items that are vintage or have a Victorian look to them. The way to immediately start creating the mood for your wedding is through the wedding invitations. This is crucial and great pains should be taken to create the right mood especially for this type of wedding. Having invitations with the Nightmare Before Christmas’s Jack and Sally would certainly convey a Halloween theme but it lacks in the elegance department. I have seen several different types of invitations that were both elegant and conveyed the Halloween wedding theme. One example would be a picture of a bride and groom embracing in a graveyard or have an invitation to a simple but elegant Victorian wrought iron design. These styles would both describe the wedding as well as the elegance about the wedding.
To create the gothic ambiance in your setting, I recommend looking for a Victorian style Mansion or even a bed and breakfast that will allow weddings. At night, these old buildings look like a haunted house which will fit into the semi spooky Gothic theme.
Our culture has loosened up on the rules of weddings which allow each couple to express themselves in ways that reflect their values and personalities. With that in mind, think about having a black wedding. This means that everyone from the bride to the groomsmen is dressed in black. You could find an elegant, black, Victorian gown for the bride and the bridesmaids. The groom and groomsmen could be dressed in very elegant black tuxedos with the tails. If you are superstitious or completely turned off by the black for a wedding gown then a color alternative could be a red gown or a midnight blue gown. If you like the thought of everyone but the bride in black then wearing a white or off white Victorian gown would not look as gothic but it would certainly look elegant.
With respect to the wedding flowers, my first choice would be black-red roses. These are very dark red roses with a hint of black around the edges. This dark look would greatly compliment the wedding theme. Other wedding flowers to consider would be burgundy Celosia, black calla lilies, and dark red tulips.
While a fog machine would add ambiance, it will also add a musty odor that may have guests coughing. So with that in mind, I would forgo to the fog. However, for decorating ideas for the reception think of have black table cloths with dark, red overlays. You could even do elegant red, velvet runners instead of the overlays for rectangular tables.
Wrought iron candelabras would make ideal centerpieces. The wrought iron look has that old Victorian look that many typically find in haunted houses. In fact, the more candles the merrier as it creates natural shadows which contributes to the spooky theme while adding soft romantic lighting.
Because everything has a dark look then your natural choice for a wedding cake would have to be something chocolate. One idea is to have a white exterior cake decorated with spider webs and topped with a tombstone style figurine. Another idea is to have a white cake with some flowers placed on top. While on the subject of chocolate, a fountain is a fun way to provide people with as many dark moments as possible.