Hi kafer,
When bubs was tiny we slept him in between us, now he sleeps between me and the wall, to avoid dh being kicked in the stomach all night (ds sleeps sideways).

I think like the other girls said, it really is instinctual. You will know where bubs is in the bed in relation to you. The only excpetion to that I would say is if you are really, really, really tired.

I did remove the pillows form our bed when bubs was tiny, so he couldn't squash his face in them, and I made sure the doona was covering me and not him to avoid him overheating.

I had a scary situtaion a few months ago where bubs had a bad case of croup and stopped breathing in his sleep. I was very lucky we were co-sleeping- I woke up immedisntly. By body just knew something was wrong- that how instinctual it is.

Enjoy your co-sleeping. there is no better feeling than watching their little sleepy pouts as they drift off next to you