UPDATE - 20170902 - Typos, finding emergency exits.
So, after many years I've decided that it's my turn to write a first-timer's guide to Defcon. There are many like it, so I'll try to be as frank as I can about the topic. I'm going to try to write for people who've never been to Defcon before (but may have been to other hacker cons). I'm not going to lie or joke around (which some of the guides tend to do) and give as much personal advice as I can. I'm also going to try to not sound like your parents, because nobody likes to read stuff like that.
It's been said that it is a common thing for people to write about their OPSEC protocols for Defcon that they don't use any other time, with the implication that they aren't serious about their security or privacy any other time and are sitting ducks any other time. I would politely like to point out that not everybody has the same threat model: Defcon has one of the most hostile network environments on the planet, one which is not often found anywhere else. It is erroneous to assume that people who only talk about how they prepare for Defcon do not take the same kinds of precautions at any other time. What those people do may not be your business or anyone else's at any other time.
To that end, here are some of the security protocols that I use at Defcon, and happen to use at other times while I'm traveling, as well as some friendly advice to folks new to Defcon.