I think routine is the answer too.
My kids have set bed times which they all know and luckily I haven't had alot of problems with any of them (Until now!)
One of my kids will actually ASK to go to bed
And one started to get into long, heavy conversations 2 minutes before bedtime every night like magic! So now I say to him '15 minutes OK?' giving him warning that 'that time' is coming up! and he's been ok.
However my 2 year old has started fighting (the first to really be a problem out of five of them) I'm not tired, I want a drink (AFTER she's gone to bed!) I've lost my dummy (or hidden it!) etc etc etc. Now I make sure she has EVERYTHING she could possibly need before bed, the not tired bit I won't argue with - It's bed time! and then when I come downstairs she starts calling me, now I answer her and after about 3 times I just say 'THAT'S ENOUGH!'
The worst is if she starts REALLY fighting - kicking and screaming up the stairs
Then I take her anyway and talk to her about 'other stuff' to try and change the subject! But I have NEVER let them 'win' (unless they are sick) because I really believe once I do that I've lost the battle forever.
Sorry to go on and on - just trying to be helpfull