It seems that it many/most families, going to bed turns into a control battle: parents always on one side trying to get kids to go to bed, and kids on the other side always pushing to not go to bed, no matter what. When you think about it, sleep is a physical need, just like food or water, and it ought to be as welcome as food to a hungry person or drink to a thirsty person. For some reason our culture sets up a situation that works against this, where it is assumed that parents must work to get their children to sleep and children must oppose. It's weird. I don't suppose primitive cultures have this tension. I wonder ...
Anyway, I'm honestly not sure how we side-stepped this control issue in our household, but we did. My children never perceived it as the parents' job to get them to go to sleep, and so they didn't see their role as resisting sleep. When they were young they seemed to need very little sleep, and I think the best thing we did was to just accept that and not spend time "trying to get them to settle." If they didn't toddle off to bed, or ask to be taken there, they would fall asleep on the couch, or in our arms, or on the floor. I guess this was flying in the face of common wisdom about creating consistent bedtime routines and such, but we didn't have a morning schedule of work/daycare/school to contend with, so it didn't matter. And the upshot is that we don't have control issues over bedtimes. Although my kids' sleep patterns have not always been conventional (to say the least!) they are generally well-rested and their choices work for them and for their housemates. And these days their bedtimes tend to be very conventional.
This is a rather different situation than those of you who are trying to transition to child-led bedtimes, of course. You'll probably have to go through something similar to a deschooling phase, where things go a little wild and wooly for a time as kids rediscover their own internal clocks and learn to recognize and respond to their bodies' signals. There will be a learning curve and I don't pretend to have experience at weathering such a transition. I would probably plan the transition for a time period when mistakes are likely to matter less but when there is still some sort of over-riding rhythm to family life ... so maybe after co-op days and violin lessons are over for the summer, but not while daddy is on holidays, for example.
In my family we all have a tendency towards night-owlish-ness and this doesn't mesh well with our need to participate happily in various activities during the day. So we do need to pay consistent attention to how our bedtimes are working for us and we manage to do so through collaboration rather than conflict. Even though we don't have transition issues that come of giving over control all of a sudden, we do have to pay attention to sleep issues. The reason this can be a challenge is that the repercussions of poor bedtime choices come much later and tend to be vague and easily misattributed. A girl who is engaged in endless bickering with her brother may be experiencing the negative consequence of her poor bedtime choice 16 hours earlier, but she is not likely to make that connection: she is likely to think that her brother is being especially annoying now, and that is all. I see it as my job to help my kids (and myself) learn to connect the dots on these issues.
Of course it does absolutely no good to point out to the girl who is bickering with her brother that she should have gone to bed earlier the previous night! When someone is over-tired and annoyed they are not going to learn from having their mistakes pointed out to them! What I've found that works best is to have discussions on a regular basis when everyone is in a reasonably good mood to revisit the previous few days and look for patterns and connections and collaboratively problem-solve. Life is full of annoyances and stresses, and I point out to my kids that they'll cope with the crappy stuff with more resilience and better humour if they have lots of well-restedness as a sort of emotional cushion. Rather than saying "You were snarky because you were over-tired," I say "It is possible that you would have been able to cope better with that if you'd been more well-rested." Rest puts emotional resilience into your tank. Life's daily trials tend to drain it out. Problems occur when there's more "out" than "in," so we need to adjust depending on what life is throwing our way. There aren't simplistic answers about what's the right bedtime or what is the right amount of sleep, but by keeping tabs on our emotional resilience and our daily activities and feelings, we can make the corrections we need here and there.
If, as tends to be the case, we find our bedtimes slipping later so that we're getting less sleep than is optimal, we look for solutions together. Once we've agreed that we're suffering from a lack of well-restedness in our tanks, I say something like "Well, then, what would help you get a bit more sleep? Is there something I could do?" We examine, and then discard, the idea of sleeping until noon, since that would not mesh with our need to participate in various scheduled activities or with dh's work schedule. So we then start looking for ways to change our evenings to make them conducive to earlier bedtimes.
I always frame the sleep-wake issue as one of a number of life-balance issues that we need to keep tabs on: sedentary vs. active pursuits, healthy nutritional balance, social vs. solitary pursuits, and so on. Sometimes we need to correct the balance in one or another area, that's all. We work together to make these adjustments, and I am always happy for any suggestions my kids might have for novel ways to tweak things. Recently I was asked to program the router to block the internet beginning at a certain time in the evening. Shifting dinner earlier in the evening has helped in the past. Dimming lights, installing a wall clock, etc.
Hope this great meandering post contains some food for thought for someone!