I picked up an entry level DSLR last year so my photos are getting better. But what's difficult is composing good shots where everything is right including lighting, smiles on faces, people facing the camera, no backs of big white shirts etc.
To get better compositions I do screenshots (on my computer) of footage in the best frames. But that's a trade off for good focus and higher quality.
Biggest things I can tell you, get a fong puffer for your flash. Don't event think about trying to get decent shots with a crop-sensor without flash. Next up, make sure you aren't getting in the line of fire of the paid photog and make sure you fire AFTER they've taken their shot. Photogs get really pissy when the DJ is taking shots and if you happen to blow one of there's out, they'll act like the world ended. Make sure you get out from behind the table and be quick about what you're doing, as well as to make sure you're not taking so much time with the camera that your client gets the impression that you're not paying enough attention to your primary duty. It's pretty easy, once you develop a rhythm but can seem pretty over-whelming at first. End result, after you start getting good images, you'll see a real boost to your bookings. They're worth the time and trouble.