Don't Get A Venue You Won't Fill

If you want a party to fire, you have to make your guests relate. It's hard to do this if they are scattered from sneezer to breezer.  People are like gas. The atoms will drift apart until they are evenly  distributed in their enclosing space. So if you hire the local golf club for a party of 30, you might as well have hired the SCG. It's better to have them packed in, especially if there are going to be speeches or cakes or other  likeminded communal activities. Whatever your numbers, you must meet what I like to call the Critical Mass for a room.  Remember, people can always leave a crowded room for a breather. But it's much more difficult to make a sparsely populated room party.

If you can do it at home you should

Lots of people want to hire a venue for their party. Some have good reasons. Most don't. Publicly, their arguments are: Want it to be great; Don't want the mess; House/backyard too small. Privately, they just don't want to wake up the next morning and have to deal with what happened the night before. Or maybe they have a thing about other people (even friends) invading their space. Fair enough. But the BEST gigs are almost always in someones living room or backyard. There are good reasons for this. Guests feel less 'public' and are therefore less inhibited about having a good time, so they do. Most venues kick you out at midnight, which just happens to be when the real partygoers are firing up. It's only the VOLUME that needs to moderate, not the FUN. It's also close to home (d'oh). Assuming that at least 50% of your guests live within cooee, it's close to home for them too. And you can have a REALLY good time, knowing you don't have to drive anywhere. And the best reason of all is that it's free. So you have to clean up. Everyone has to pay the Piper sometime, don't they?

Where to site the Bar

A Question like this has many answers, Grasshopper. It really depends on what the layout of the venue is and how many guests. But general rules of thumb are:
Have only one bar area. This area should have at least two distinct avenues of approach for punters. If you are having bar staff, then try to site the bar so that they can get in and out (for supplies) without having to go through the punters. If you have a band/dancefloor etc. don't site the bar front or sides of 'stage' as it is just bleeding dangerous. In this case, setup the bar at the back of the room, in the centre so that there is a natural flow-through and people at the bar can still be involved in the action. Don't put the bar in a laundry, or bathroom. It might seem convenient, but it's a choke point...

Sit down versus stand up

Sit down dinners are very appealing. You get the tableware, the party poppers, the pecking order of who' is on whose table... You also get tables and chairs that take up amazing amounts of space. As a bonus, you get served a three course meal which takes up an equally amazing amount of time. And that's the crux of the biscuit. I have lost count of how many times our band has been hired to play a sit-down gig from 9-12. Post dinner, speeches. auctions or whatever, we invariably sit around until 9.45-10 or even later. No problems there, we still get paid. But the punters miss out and in more ways than one. Remember the tables? You actually have a LOT less people than you think, as the tables and chairs use 75% MORE space that the folks occupying them. If you move them out, you now have an empty room(So What?) As a band, playing to people who are seated at tables is like pulling teeth. If there aren't some go-gettin' gals out there that just want to up and dance (hate to say it fellas, but it's never you) you could have a Led Zeppelin on your hands.
So if you're having a band and you can swing it, don't let the guests sit down to dinner. Have food served by all means. 'Finger food'  can be top quality AND nowhere near as expensive as full catering. You can always get friends or others (or gasp- even hire!) some nice people to wander round with plates of goodies...

Wet Weather

Mostly, DiscoDudes can continue in damp conditions. For bands, water is a serious disincentive to play. Getting electroluxed or doing the charred fandooglie is not on the Musos Most Wanted list. So have a wet weather plan. Discuss it with your band. Listen to what they say, they've had more experience than you. Never assume the weather will be OK. Some of the most memorable parties have been held in pouring rain with wind howling up the wazoo. Strange it may be, but people always seem to pull together in adverse conditions and those parties are always fondly remembered. Sometimes because Geoffrey was standing under the tarp full of water when it collapsed.

Neighbours

If you can stand them, invite them. Give them plenty of warning regardless. Print out a handbill and drop it in their mailboxes. Don't tell them chapter and verse, just that you're going to have a party, that there will be lots of cars and a live band and the date. If you are really worried that they are going to  call the constabulary on you, beat them to the  punch and visit your local Police and let them know that you intend to be resonsible citizens, provide them with a contact name/number etc. They'll appreciate that if irate neighbour then calls in...

Power and Light

If you are goint to have a band at some hired venue, you probably don't need to think about this if the venue has had bands before. If not or if the venue is your house, consider this: the stage amps and paraphernalia use about 500W. For a small PA, another 500-1000W. Lights chew power. For a small venue, 1500-2400W. For those without a degree (and living in Australia), 2400W is 10Amps, which is about all you want to pull out of a power point!  So it's relatively easy to supply power for the sound, but not so easy for lights. When you hire a band, discuss the power with them. Know where your fusebox is!

To Band or Not To Band?