Yeah, this is the advice I've always seen with sleep training. It's important to put them down drowsy but awake. I find this extremely challenging. If the lights are on I can tell, but when it's night time and I've got the lights out I have no idea when he's drowsy but not asleep yet, and he's extremely light sensitive so I can't just have a light on. So I often accidently put him down asleep and he actually does just fine.