I know there are a lot of photographers who leave the reception straight after the first dance. I am at a wedding for a minimum of 10 hours and have been known to shoot for 14 hours!! I love photographing dancing at the reception. This is the time when people have forgotten all about me and are just having fun!
The trick with getting great dancing shots is having eyes like a hawk and watching where the action is! Don’t be timid, if you see someone going for gold get in there and shoot! Lie on the dance floor, stand on chairs … get a different point of view. Learn how to use your flash properly so you can balance ambient and flash light. I never use my flash at more than half power because of flash duration issues. If you use your flash at half power or lower it should freeze movement. Make sure that you have lots of batteries on you so you can swop if you run out of juice. The same goes for memory cards. You don’t want to miss any action while running back to your bag!