One of the things the authors talk about in "Your 3-Year-Old: Friend or Enemy" is the need to help the kids save face when they disagree with you. I've found this to be very helpful with Michael. It really helps to diffuse his natural contrarian leanings.
Setting: Living room shortly before bedtime.
Me: It's almost bedtime bud.
Michael: I don't want to go to bed. *rubs at red eyes*
Two minutes later.
Michael: Mommy, is Larry tired?
Me: Yes. Do you want to take him up to bed?
Michael: *grabs Larry and heads for the stairs*
It's so nice of Michael to sacrifice staying up late just so the very tired Larry can get some sleep.