DS doesn't relax his jaw until he's really dead asleep. You can toss him into bed at that point, and he stays alseep... unless you didn't tell him about the "I'm taking my boob back" bit, at which point you won't get that far

. I usually do end up kinda tossing him, actually, becasue some portion of my anatomy is usually asleep by then

We used to change his diaper after he was asleep pretty regularly, and I've been known to get him dressed from diaper to snowsuit immediately after taking him off without waking him.
It doesn't help for NCSS in any way, because there's no way to gradually change it.
Light levels: yeah, he's had some phases about light levels. He was quite affraid of the dark when he was 3-6 mosish. But he got over it, and now particularly likes a very dark room, but will sleep in any light level. He sleeps anywhere, and usually gets pegged as a good sleeper. He once slept through a rocous party, including the part where someone tripped over the stroller he was in, while carying an object which could not be allowed to touch the floor. It was... impressive...

. But then we left, and shortly thereafter he hit the end of his sleep cycle, and we had a nasty trip home. But nobody saw that part. We're famous for our good sleeper. <sigh>
Like I said, we've got a situation that mostly works, though it's not perfect. He's working on it, and, frankly, I trust him.
Untill recently, he never really had a cry that didn't escallate very rapidly, and he does remain upset for very long periods of time (hours or days). He does cry mildly now.
Oh: and books. He doesn't read yet, but we do read books to him at bedtime. That's fairly recent, because for a long time we couldn't have any kind of "ritual" or else his stress level would start going up at the beginning, and it would become impossible to get him to sleep. He does seem to appreciate having a bit of a routine now, but we still keep it pretty short and low-key, because sometimes he still gets the stress issue, and it's not very predictable.
We also do a quiet time before bed now, which used to create problems, but I really have trouble not having it! I think it sometimes helps, and sometimes makes things harder... hard to really say on that one.
-Mich