Hmm - let me think
railroading - sometimes. I try to avoid it. I've gamed with these guys a long time, but they do still manage to suprise me. Out of the seven, there are two that are really driven. But if both of them are having an off night, we get to the point where I say (jokingly)
"...and the bold heros look at each other indecicively!"
Also, I get irritated if someone's character wants to go too far outside my idea for the campaign. I'm not a total a-hole about it, but for instance one of my younger players said he wanted to become an assassin. I flatly told him that wasn't going to happen. This is an epic, heroic campaign - assassins are the enemy.
I also tend to strongly discourage evil characters - I don't like them, its not the kind of game I run. You are out to save the world, not concot evil schemes. Taking time to deal with someone doing that wastes my game time, which is precious to me. If you want to do that, talk someone into running a game more to your tastes or run a game yourself.
I used to be bad about over preparing - one hour of prep per hour of game. I've got that up to probably three or four hours of play for each hour of prep.
I tend to be fast and loose on the rules - we play marathon games, last one was fifteen hours. After eight hours or so, I might not be clear on if, for instance, you can rapid shot as a standard action or full attack only. I let someone do it as standard last time

. And no one else knows the rules well enough to call me out on stuff.