I co-slept for 2 years with my first son and so far 11 weeks with my second. With both its been different.

My first would literally only sleep if he was held, by this i mean i lay on my side with my arms around him like a cuddle. I am a light sleeper and tend to stay in one place, i would wake up still holding him. He fed hourly too so neither of us fell in to a deep sleep really. Even up to 2 years he still needed to be held to sleep... he's in his own bed now, but myself or husband lay with him until he falls asleep.

With my second son, i just put him in the middle of the bed between my husband and i, but up between our pillows. So his legs come down to my shoulders sort of. Our pillows are about 30cm apart. The quilt goes up to his waist.

I think your instinct kicks in at some point, because at first i felt scared to co-sleep, but then i became so in tune with my first son, that i woke when he was "mouthing" for a feed before he even cried, and i think that comes from being so close together. I became to trust myself that i would instinctually never roll on him.

The kidsafe website has some great co-sleeping tips for safety.