In this article, I will discuss the usual characteristics of what is called a "formal" wedding. Weddings, like many other events, are usually considered to be either "formal", "semi-formal" or "informal". Unsurprisingly, formal weddings have the most stringent set of characteristics to be considered "formal". In this article, I will discuss the basic criteria of a "formal" wedding, if that is what you wish to go with.
The wedding itself usually takes place in one of two places. If it is a religious wedding, the wedding will usually take place in a house of worship. However, the level of decoration will be much higher in a formal wedding than in either a semi-formal or informal wedding. Further, the attire (which I will discuss later) will be formal. Nonetheless, most houses of worship don't really distinguish between levels of formality in how they perform weddings. If it doesn't take place at a house of worship, formal weddings usually take place either outdoors or in a large home. Note that formal weddings do not generally take place in reception halls. Formal weddings are "hosted", in the sense that the entire event is arranged by the host (usually through a wedding co-ordinator).
There are usually a number of attendants in a formal wedding, about seven or eight per side. You'll definitely need them. Due to all the extra details involved in co-ordinating a formal wedding, and army of helpers certainly helps. The attire for the wedding party is extremely formal. Men (including the groom) will usually wear tailcoats, a style of jacket in which the back is significantly longer than the front. Women will wear long, formal gowns that look significantly more formal than the typical bridesmaid dress. Cultural clothing is also appropriate, but the couple and wedding party should be sure to wear the most formal attire available in their culture. For instance, don't just wear a kilt, wear a Prince Charlie jacket.
The dress of the guests will vary according to the time of day. In the evening, male should wear tuxedos, while female guests should wear either formal gowns themselves, or smaller cocktail dresses. Since many formal weddings are held outdoors, the weather will often dictate what is most convenient for the female guests. For weddings held during the day, the level of formality for men decreases, and men may wear dark suits, while gowns become more appropriate for women.
The reception itself is usually a served, seated dinner served by waiters if held in the evening, though during the day a buffet may be more appropriate. Because formal evening attire can be difficult to move around in (especially for women), you should avoid a buffet dinner in the evening. Music should be played live, and partly because of formality, and partly because freeform dancing is difficult in formal dress, you should avoid music that is too heavy.