Sure, it's an honour to be chosen as best man--but there's a lot of pressure involved, too. He has to plan the stag night, remember the wedding rings, and, of course, stand up in front of all the wedding guests and deliver a killer speech without embarrassing himself too badly. One of the keys to a good best man's speech is hitting all the sweet spots in the right length of time: between 5 and 10 minutes should do it.
The Opening Lines: 1 to 2 minutes
The opening remarks are generally the most nerve-wracking part of any speech. A best man may find that a solid way to start is by briefly introducing himself and describing his relationship to the groom. The other wedding guests will be naturally interested in his relationship to the couple, so certainly this will hold the audience's attention for a minute or so. If it's in your nature to be funny, you can also start with a quick joke or quip about the groom or couple that the audience will appreciate, and then launch into your introduction.
The Story: 2 to 4 minutes
The body of the best man's speech is usually a story about the groom or the couple. Popular themes include how the couple met, an incident in the couple's relationship that exemplifies their relationship, how the groom has changed (for the better) since meeting his bride or the groom's achievements in life. Keep the story to 4 minutes maximum, unless you are certain that the topic will have the audience rolling in the aisles or otherwise gripped by every word.
The Wrap-Up: 1 to 2 minutes
At the end of the speech, the best man should talk about his good wishes for the couple, and in particular, the groom. Without revealing too much of the groom's confidences, the best man may talk about the groom's hopes and visions for the future, mirror these wishes or expand upon them, and raise a toast that these happy dreams may come to pass.
The best man should speak slowly and clearly. The other wedding guests will appreciate it, and it will help calm his nerves. He should also practice the speech several times before delivering it, preferably in front of a friend who can give honest comments. During the practice sessions, he should time the length of the speech to make sure it doesn't go on for too long or isn't too short.
Even if nervous, the best man shouldn't drink too much before giving the speech: too much alcohol can result in slurred speech and a tendency to ramble. Also he should avoid any topic that might embarrass the couple, particularly the subject of ex-girlfriends, ex-lovers or ex-wives. Embarking on awkward topics such as these can make the speech seem much longer than it actually is.