It was a few months before we actually had a feed play sleep cycle. DD was a real booby girl and so she used to often like feeding to sleep. So I'm not much help with distinguishing between tired and hungry cause I'd put her on the boob for both. I guess you could see how long since his last feed and how well he fed for it and how long he has been awake for.

I sort of just went with the flow til she fell into a pattern on her own. I don't think I really noticed a routine til she was about 6 months.

The other prob we had was she was a cat napper, only would have 30-45 min naps during the daybut as she was happy (generally) in her awake time it must've been all she needed.

I suggest just going with the flow, if he is tired put him down if he's happy being awake so be it. Eventually he will find his own pattern.