Have a large scotch.
Do NOT just read it out from a set of cards. People will look at the pile and think "Hmm - he's bored us fartless for 10 minutes and he's only about 1/4 way through his cards..."
Think of a structure.
Write down some cue headlines to remind yourself of what you were going to say.
Be natural between the headlines - and only use jokes/anecdotes which are appropriate and which you can remember.
Keep them interested and guessing
Don't use TLAs, service slang or yoofspeak.
Check your flies.
Don't stare at the girls' tits.