I'll answer the opposite question; follow none of this advice and you'll probably have a winner.

How to make an awful hackathon:

1. Familiarize yourself with the "hacker league" but don't affiliate with them; better yet, check their schedule so you can pick a date that conflicts with a better hackathon in the area.

2. Require that all submissions be new work, but limit the winners to people who have demonstrably worked on their entry for weeks.

3. This one I picked up from TechCrunch Disrupt SF- determine how much square footage your hackathon used in previous years, then try to cram the next year's into a space half that size.

4. Also from TechCrunch- get some A-list VC's to speak, then put no effort into soundchecks to ensure people can actually hear them.

5. Put no one in charge of making sure the event is lively and safe. If participants get the laptop stolen out of the backpack they're using for a pillow, or get drenched by a super soaker, that's their own dumb fault for bringing a computer to a hackathon.

6. Make all of your prizes in-kind donations of services that hackers either already have in spades or would never use, like discounted Rackspace hosting, entry-level coding classes, or unpaid internships with your own firm. Never offer cash, as the best hackers treat cash offerings as an insult to their professionalism. If you have to offer cash, make the cash a nominal amount, like $10. Better yet, make it a starbucks gift card for $15 - whatever your favorite drink was when you bought it. During the awards ceremony, announce the recipient of the card but never see they get it.

7. Start advertising for your event three months out, then stop the advertising two and a half months out when you run out of time or money. Make sure no one carries any updates about your event so it can happen quickly and quietly. Only the best hackers will show up because they hate competition, have long memories and mark their calendars. Advertising really is a waste of money and most people spend way too much on it.

8. Make the presentation process as frustrating as possible for presenter and participant alike. Give people less than 5 minutes to present their idea, and ensure that everyone spends at least 3 of that trying to figure out how to make your AV system work. Ensure you're violating the fire code by making the space small, and make the speakers and projector (not projectors) undersized. Make sure your projector connection is Thunderbolt (for windows-themed hackathons) or HD15 VGA (for Mac-themed hackathons).

9. Charge for admission to make clear how you're underwriting the event. If you offer $5000 in prizes and expect 100 hackers to show up, charge $100 per entry. Better yet, offer a dual-tier charging structure so prospective investors and members of the public pay nothing. Don't bother checking if the free tier submits entries. Also encourage the free tier to mingle with the hackers while they work. Hackers need suggestions.

10. Cater the event by the lowest bidder. Costco pizza and Coca Cola products are looked upon fondly by hackers because they don't care about their health. Offer lunch leftovers for dinner, dinner leftovers for breakfast, and so on. You should only really need to place one order of food. Offer an unappetizing vegetarian option and don't label it. Leverage your frugal use of space by doubling hacker workspace as the line for the food.

11. Ensure your event has too few bathrooms and too few garbage cans. People can crap and throw their trash away at home.

12. When winners are announced, do it on the down low. Don't put that information on your blog, so when 2019 rolls around and someone wants to find out who won or attended, they can't.

13. If your projections show you'll be able to sell 1000 tickets to hackers at $50 each, use an easily-gamed system that makes 2 batches of 250 available for $25 each at random unannounced times. Selling out your event ensures the highest quality of hacker.

14. Buy (6) 3' power strips from Costco and leave them unopened in a corner of the space. For Wifi, use whatever the building already has available. Make the wifi password more trouble to ask for than it's worth.