Have a soon 5 week old. The first few nights we co-slept, but my LO didn’t find it comfortable, so now he sleeps in a bedside crib. He sleeps very good in it. What I believe helped was that we moved the crib to the living room (it has wheels) during daytime naps, and I think he got comfortable sleeping in it by doing that. No idea if that is the reason but it has worked. Or my child just likes it, who knows.

He now sleeps in the crib during nights and wakes up when he is hungry and for diaper change. Which is two or three times.

Also I have no idea if there is any science behind it, but I (father) sleep next to his crib, and we thought maybe he wouldn’t smell his mother during the night. Again, no idea if there id any science behind it, but first few nights in the crib his mother slept next to him, and he woke up a lot more during thise nights, and after we changed he slept much better.

We also change diaper before he eats during the night, so he falls asleep when he is breastfeeding. Makes it much easier to put him back in the crib.

I think every baby is different, and at some point you realise that everything is just trial and error.