Down to sleep at night

Babies get to fix their own schedules after a while. It usually suits your family's needs too.
Liam out of the blue started falling asleep for good around midnight. Of course midnight is a good hour but I wanted something more like 10ish.
Searching on the internet I found out 2 very important things for being able to put him down to sleep:
1) put him down at the same hour
2) don't let him sleep after 7pm

How I do it: Unfortunately, I'm not so good at keeping a fixed schedule (my household can't manage it) so I work around it. After 10 - 10.30 pm I can focus on putting Liam to bed.
If he doesn't already fall asleep in the living room , we go to our bedroom (we share bedroom) where I dress him in pj's, give the pacifier and put on carrions (a whole cd, on repeat).
Now he's 4 and a half months old and usually he falls asleep like this. At times he keeps me close by not letting go of my hands.
When he was a lot smaller I used to rock him (now he's too long and too heavy) or he would fall asleep at the breast.

However even if my efforts to put him down to sleep at 10 - 10.30 fail he stays in his crib playing and falls asleep for good at midnight.