How to be a good club photographer?

Here's a contentious question on photography: something for the photo guide on how to take a good picture on a night out. It's an issue I was avoiding, but people seem to want it. Here's what I have so far in the guide:

• Frame the shot properly in the LCD if possible — it saves time editing afterwards. (Taking photos is fun, editing photos is boring.)
• Most cameras advise "save battery by not using the LCD or flash," but you need both for clubbing. Take spare batteries. Take a spare card too.
• Don't just photograph people's face and shoulders, get a full-length shot as well — their outfit will have been planned from top to toe. (courtesy ciphergoth)
• You can't use flash in smoke. Don't even try — just set the camera fast and brighten the shot later. If you must use flash in smoke, turn saturation/vividness down.
• Sort out permission from club and subjects sensibly. Use common sense — upsetting people is bad. (noted by bramsmits)

This is well out of the technical area and into matters of opinion. And I really don't want to end up inadvertently writing a book-length list of ideas and side-issues. But what works for you? What obvious errors do you get sick of seeing that a non-technical automatic photographer could fix easily?