The supply of liquor in this tweet below probably was more symbolic than functional, but I have heard other stories about people getting offered a drink back stage before appearing in a major TV broadcast.
A bit of alcohol relaxes nervousness, but it is actually not the sort of relaxing you want on stage. You need to be sharp and switched on to remember your story and react to audience feedback. Some other things you can do to deal with nervousness:
- Know your story inside out, rehearse, rehearse, rehearse. Seth Godin suggests that you can even start with dogs as your risk free audience. Work especially hard on the opening of your presentation, since these are the most difficult moments. Once you are on a roll, the rest will follow much easier.
- Remember that everyone (including the pros) is a little nervous before going on stage, remember that a bit of nervousness gives you the right alertness to deliver a good performance (alcohol does the opposite), remember that the audience wants you to succeed there, remember that for most people stage fright is like that first chill when jumping into a pool, it is over in 2 seconds once you get going.