Wedding speeches are after dinner speeches
Never speak to an audience that are either hungry or thirsty.
It is common practice for most Western weddings to include a round of after dinner speeches from, the father of the bride, the groom, the best man, and sometimes nowadays the bride and the matron of honour, although not obligatory.
Whether the wedding is a formal or a casual occasion, it is usual to have the speeches after dinner when the bride and groom's butterflies are likely to have subsided, guests are more receptive and any children present are not overtired. It is not a social faux pas, however, if it is decided to have the speech-making before eating, it is simply a matter of choice. Most speakers will find it easier to speak after dinner when people are still seated and the atmosphere is relaxed before the guests start moving around, dancing and generally having fun.
The after dinner wedding speech may be either formal or informal, depending upon the event itself. It is unlikely to have a formal wedding in Westminster Abbey followed by casual wedding speeches or to have an informal wedding with ceremonial speeches.
Regarding the sequence of speeches, the general rule is for the father of the bride to speak first, usually a short, humorous speech along the lines of gaining a son. After the father of the bride's speech comes a few words from the groom, during which he traditionally thanks his new father-in-law and his bride. Nowadays it is commonplace for the father of the groom to say a few words too and, if this is to happen, he should stand up after the groom. The best man is the last male to speak and is expected to make a good-natured, funny speech about the groom, and ending with a toast to the bride and groom. If she wishes, the bride can now stand up and make a speech of her own, with her matron of honour or chief bridesmaid as the final speaker.