Make a guest list
The only rule when it comes to a guest list is that you absolutely must have one. Your aim should be to strike the perfect balance between that friendly inclusiveness that makes people feel welcome and that intimate exclusivity that makes those invited feel as though their presence is personally desired. There’s no bigger turnoff than the “I just invited everyone on my friends list” approach.
Decide what your guest maximum is based on available party space and then narrow down the number based on how intimate you want the event to be. Not sure where to cap the head count? Take a look at this numbers chart:
10-20 people: Not a party as much as a “gathering.” Depending on the size of your place, 10 to 20 people will comfortably fill all the available seats in your living area, roughly. If you’re looking to host a fun evening with enough people to create a “mingling” atmosphere, but not so many that you branch outside your inner circle, this is the number to strike.
20-40 people: At this number, you’ll have a nice little party going. You’ve probably branched a little ways outside your tightest group of friends, and because of that, you will have to play hostess a little more. At 40 people, your party has the potential to get pretty wild, so bear in mind that you will definitely be spending more time making the rounds keeping people in check. That being said, 40 people will definitely get the party started, to quote the immortal P!nk. P.S. Don’t play that song though, for the sake of your party.
40-60 people: This number may not seem large, but it is. You’ll get the killer party you want, but bear in mind the amount of drinks 60 people can spill, antique vases 60 people can break, wood floors 60 drunken girls in stilettos can scratch, etc. However, 60 people will make for quite the soirée, so if it’s a big bash you’re looking for, a big bash you shall receive.
60+ people: Okay, so you’ve decided to throw a big party. Some people invite fewer guests to their wedding. As long as you know what you’re getting yourself into, a party with over 60 guests will achieve the raging status you likely want it to hit, so go wild, you party girl.
Bear in mind that not everyone you invite will be able to attend, so if you’re determined to arrive at a fixed final number, send out invites to a quarter more than the number of people you hope to ultimately host. As far as plus ones go, take a stance, be it staunch or liberal, about additional guests. While it may sound a bit judgey, it’s best to decide on a guest-to-guest basis who’s welcome and who there isn’t room for in a party at which you are liable for your invitees. There’s a difference between a good friend bringing along his visiting girlfriend from out of town and a somewhat-acquaintance stringing along his entire lax team (though we might not complain if it was the lax team).