EDIT: By the way, how do you start your games? It's something I've been having a lot of trouble with. Do you find that the old "you all meet in a tavern" does the job, or do you try to be more original about it? I have the kinds of players that are inclined to wander off and split the party at every opportunity, so I have to go out of my way to justify the party sticking together, and I always find there's no way to guarantee it without railroading. The end result, of course, is that I scrap every first session I plan.
20 pt buy, book races/classes, and I let the plot of the adventure determine where they start and how/if they know each other.
And I mercilessly crush party-splitters merely by using the wandering monster chart, or a mugging, etc.
Party-splitters are universally attention whores who can't cooperate on SHIT, and deserve everything that happens to them.
Players who see the plot hook and deliberately avoid it (and they always have excuses, like "What's my motivation, here", as if they were a bad B movie actor, or "I'm only playing my alignment"...WHO CHOSE THAT ALIGNMENT?) should be immediately dumped in favor of either a smaller group or another player.
I am known as The Table Nazi, but amazingly enough, I have 2 campaigns running, and a waiting list on either one. Because I don't tolerate that sort of shit...It ruins the game for everyone except the useless attention-whore.