If you're talking college status rager, not just 20-30 friend get together, do as follows:
1. Get a playlist of at LEAST 100 bangers (Rap, EDM and songs to cater to the women, but still bangers) on your iTunes. Get the remote app for your phone, so you can stash/hide your computer and can connect it to your speakers while still being able to control the music. This prevents your laptop or phone from getting stolen in the event some whore decides she wants to play DJ and play one fucking song she thinks everyone wants to hear while she disconnects your iPod thus leaving it exposed to being jacked. (happened to one of my roomies at one of our parties)
2. Always buy alcohol and chasers to provide for the party, but still tell people to BYOB. Buy half gallons of the cheapest of the cheap, like the 15 dollar half g's. When people get hammered they won't be able to tell the difference. Also, DO NOT CHARGE MONEY FOR THE ALCOHOL (yes, even dudes). The point of a party is to invite people over and have a drunk/awesome time, not to make money. Plus it's a bitch to try and collect money from people if you're charging, plus they'll figure out a way to get the alcohol anyway if they claim they are broke, trust me.
-You'll obviously want to buy enough alcohol. I'd say 5 half g's is good for about 80 people. But then again we threw a party at our house that had 200+ people and still growing, and we had bought 10 half gallons and all of them were gone within 45 minutes of the party starting.
-If you want to go above and beyond, we would always set up a table with dixie cups, half of them filled with shots and half of them with chasers that people can grab and take. My friend would often bartend just to keep track and refill cups. Plus if you bartend it's an awesome conversation starter, especially with chicks.
3. If you're planning on throwing a legit rager, shit will get broken. There's no stopping that, so hide all your expensive shit (flat screen tv's, etc.). Above all, LOCK YOUR BEDROOM.
4. Don't buy food platters or anything else gay like that. People will probably eat before they come over and don't plan on filling their stomachs with anything but alcohol. Plus that shit gets messy.
5. Have a beer pong table set up. When the party is starting off and there's not many people, BP is a way to get things going. Imagine if you walk into a place early where people are just sitting, drinking and talking. Lame, right?
6. Have your good friends come over early. Lay a foundation of people down early for people coming early. The party will seem more crackin' (even if it's not to you) to people who don't know you real well because they'll just associate the number of people with a decent party that early on. Plus if it's random people showing up early, you don't want to be the only one trying to entertain them.
Last year we followed this formula every party we threw and all of them were ragers, so I'd like to pass on the knowledge