Play Sweet Shop fifteen times in a row.
Stay calm. Meditate on your tunes beforehand and just get into the flow. Make sure to watch your audience carefully; I can't stress that enough. That is the staple of a good DJ (at least before you're famous and people are just coming to see you to hear your tunes). Look at body language and try and gauge their emotions. Don't compromise what you want to be playing, but improvise carefully, so that you can get them to follow you on your little journey.
Just remember, you're not just playing music for people. You're telling 'em a story. YOU are the guy who can turn their night from a good night into a great night, and take pride in that fact. Stand tall. You're the tribeleader at the campfire.
If you arent having a good time, they arent having a good time, just relax. Took me years to learn that.
Had my first time playing out a couple of weeks ago. Though it wasn't to many people, the one bit of advice that I'd give is just relax. You know you can mix well (I assume), you do it all the time (also assuming that), so just get into your regular flow and enjoy it. Play what you want to play, and an open mind to change the vibe as you see fit according to the crowd's reactions to certain tracks, etc.RELAX is the key word though.
lol'ed @Sub-Radar-Mike.but seriously just have a laugh init.
Though I haven't DJed to a crowd myself, I'd say that as long as you're having fun and feeling that's what matters most.If I can see the DJ up the front having a good time and getting into the mix it definitely gets me into it more.
Stay calm, have a varied selection to hand, keep an eye on what the crowd is responding to. Enjoy it :)
Have a good time and relax. Before you go on you will probably be pretty nervous but once your on, the time will fly and you won't want to come off.