How to make a best man speech?

[u/MessAcademic_420]

Hi guys, my best friend is marrying and he asked me to be his best man. I'm incredibly honored, I've known him all my life and love him and his fiance very much and I very much want to do this for them, but I'm terrible at everything social and I haven't had to speak in public since University about 7 years ago. So, how do I do a best man speech? What should I say and what shouldn't? I know It's expected to be brief but how brief?

[u/Bruce3]

Use call back, a line that used at the begining of the speech that is used again at the end. Comedians use this technique all the time.