Pretty much the same everywhere
Dan Drezner posts advice about what to do (and not do) at political science conferences. Kieran Healy offers advice about what to do (and not do) at sociology conferences. I find it curious that their advice pretty much applies to economics conferences as well. (CalPundit thinks it is more than just an academic thing.) I have only one thought to add: the big names can be really, really dull. I once attended a session to hear a paper by a distinguished economist at Berkeley, and nearly fell asleep while standing up. I could not imagine a duller, more pointless paper. Afterward, I got a chance to read the paper, and I was amazed how much better it was in print. I don’t mean that big names are necessarily dull by any means. Some are remarkably good. (I’m told by macroeconomists that Brad DeLong is very funny.) I note only that being a good economist is no guarantee of being an even tolerably coherent speaker.