I had the pleasure of being best man, the speech went really well. People patting my back afterwards, however pretty much every bloke in my direct family began crying.. very worrying!
Get a good solid friend that has spoken before to help you right it, funny memories are always good, plenty of smiling whilst delivering the speech. Props work well I wish I had a video of the last wedding I went to where they had a timeline of the grooms life with it ending as himself with a life size Tin tin cut out! Best bit of advice is to practice the speech out loud, get the pitch and tone of your voice right for the delivery, maybe get someone to listen to you so you know how uncomfortable it is to speak out aloud. Gets rid of any gremlins.
DONT
Swear
Drink too much - a glass or 2 first..max !
Dont make it up as you go along, sometimes you have to make up the odd bit-
My voice had a dodgy spell when I stood up, had to make a quick joke about puberty! (Went down a storm as look like im barely 18!)
DONT - CONT
Crack in jokes that nobody else will know
Speak to fast
If you can get someone to film it on a phone or decent camera or even video camera it will be good to look back on in years to come
Also so we can watch! haha!
Best of luck!