What are some tips for someone attending a hackathon for the first time?

I'm writing this from the perspective of an active Hackathon Hacker as well as form the perspective of a Hackathon Organizer.

1. Have your backup internet access ready - Get some 3G data or find a student who can share their university network with you. The possibility is very high that your internet will suck, so better have a backup ready.
2. Work on your pitch - I saw many great projects not passing to the next stage, because they haven't put effort in their pitch. I am always amazed what people can accomplish in 24h, but the reality is that you have only 2-3 min to convince the Judges how amazing your project is.
3. Sleep between 12am and 3am - I noticed that the people who do get some sleep perform much better. Most of the people try to pull an all-nighter and end up with a bug at 1am and need until 6am before they can fix it. If they had just got some sleep they would fix that in no time. And it's better to sleep a bit earlier than the others. At 3am you will have super fast internet ;)
4. Don't jump into coding immediately - Discuss and have some fun brainstorming first. Even if you spend 4h on that. It's better to have a clear idea and a master plan for the next hours than produced code which doesn't lead to anything. I had to learn that the hard way. In my first hackathon we ended up starting from scratch again at 3am, because the initial idea was crap.
5. Walk around - Spent some time off the screen and talk to other teams. Hackathons are a huge networking opportunity and you don't always have the chance to find so many talented in one place.
6. Handle travel reinbursements - Have travel reinbursement? Make sure you handle the paperwork / talk to the persons in charge, already during the hackathon. It can be hard to approach organizers after the hackathon, because they are trying to 'get their lifes back' after working so hard for several months.
7. Say thank you to the organizers

Edit: I originally posted this on Quora. As a proof that I am the author, I added a backlink to this article on the Quora post:
https://www.quora.com/What-are-some-tips-for-someone-attending-a-hackathon-for-the-first-time/answer/Long-Hoang-4