What problem does this solve?
Organizing something big must be exciting (like, properly exciting, with twists and turns and "OH NO!" moments), to be able to get that "we... survived this, somehow" feeling in the end. Which is, let's be honest, much more comforting than a simple "that went well". While the previous help for this is no doubt useful, it might not be enough to give you the full "everything is terrible" feeling. Add all these new and exciting mistakes and you'll certainly be ready!
What is the solution?
Planning and applying for financing
Put together an ambitious application, plan for massive participation.
Amongst the goals to be achieved, include a dramatic positive impact in the social consciousness. Call for large-scale communication on every stage of the project, without specifying who will communicate, through which channels, and when and how will the message reach its target audience.
Plan to have thorough feedback, with surveys before, during and after the event. Don't waste your time with details like why you're asking these specific questions, who should ask and analyze the answers, and what to do with the results.
Send the application and forget about it for a while.
When you find out that the application has been accepted, don't bother to read it again, just start organizing the event.
Find various partners, specify the areas of responsibility, but do not assign them clearly. Collective management leads to collective responsibility! (or lack thereof).
Make sure all communication between the organizers happens on Skype or through Facebook chat. Keeping proper written documentation is for the weak.
Don't create any page or database to store the contact data and responsibilities of different organizers and partners. People don't like it when you bother them about something they promised to do.
Choose the catering for the event with the basic premise that the one dish that is offered should be free from everything: meat, gluten, flavour, you name it. People won't go there to eat! And afterwards you'll get fantastic feedback about the attendees' new culinary experiences.
Cover the expenses from different bank accounts, and don't specify that the payments are related to the project. You'll have a lot of fun putting together a financial report, and your accountant will get a lot of valuable experience.
Are most of your attendees computer geeks who use two or three electronic devices at the same time? Just hope for the best, and don't bother to check whether the venue has a working Wi-Fi connection and enough electrical sockets. I mean, how couldn't it? It's the 21st century after all.
Stream the presentations on Facebook or YouTube, don't bother thinking about saving the files. What's the point of keeping files around anyway? Of course, you will only remember that you promised to give those files to the National Archives as part of your application once you start writing a report and actually read that application again. Don't speak with the venue technicians before the event starts; in fact, wait until the event is over, then the conversation can be more relaxed.
When welcoming guests, you shouldn't check whether they have paid the conference fee. It's ok, they'll know if they have. No doubt you'll enjoy the very interesting creative exercise of reconciling the budget afterwards.
Don't inconvenience the presenters by asking them such questions as what license their presentations are under. Also, there's no point in asking for all the slides: nobody will want to read them anyway, and if they do want to, they can read them from the Facebook video! No doubt someone will be interested enough to upload them on their own website anyway.
Don't even think of giving out the feedback surveys during the last day of the conference. Let the attendees go home and answer them two weeks later, when their thoughts are no longer clouded by all the things they've experienced.
Create four different websites for the event, and don't bother keeping their contents in sync. Any questions that the potential participants can come up with (such as what's the abstract submission deadline) will be much more entertaining if different sites give different dates. To make it even more fun, it's a good idea to change the deadlines and other information from time to time (but only on one of the sites, or via email!).
Promote your event through mailing lists for university students, and nowhere else. After all, young people are the future, right? There's no need to inform the media, they'll hear about it somehow anyway. Then you can explain in the report that the small scale of the event made it more cozy and enjoyable.
Make sure not to reach any agreements with anyone about media coverage for the event. That's the kind of thing that must happen completely spontaneously and always come from the heart.
Write to all the organizers a couple days before the deadline for the final report, and tell them it's time to get started. Most of them will answer, and start doing their best to remember something while dealing with all the new projects they're already working on.
Read the application. It's very interesting, full of ambitious ideas and goals. Think about how to twist reality around so that it matches the application it at least some ways. It's entirely possible that, while working on it, you'll also make some new discoveries in the fields of theoretical physics or quantum history.