My son sleeps with me/us quite a bit. We did a week of co-sleeping when he was about 8-9 wks old or so after the bassinet then he went into the cot. He does pretty well in his cot generally, but since he was about 5 months old his night sleeping has been out. He starts the night out in his cot but can often get really upset when he's put back in his cot after one of his night feeds. At that point I'd bring him in with me. But in saying that, DH has been away for 6 weeks and will be back tomorrow so the co-sleeping won't be happening as much as I don't feel comfortable with the 3 of us in the bed because it isn't a big bed.
When it's just DS & I, I take out all the pillows bare one thin one for me and make sure that no covers etc are near DS. But you also need to feel comfortable and know how your bub sleeps - once my son is asleep, he doesn't move at all, so I'm comfortable with him being with us. If he was a wriggler or moved a bit, it would not be happening.
Also can I just say - there are SAFE ways to co-sleep. E.G., look up a sidecar cot. This is a good idea for younger bubs who are still swaddled and not rolling. Another one is an arms reach co sleeper, I know some babies frmo my birth group are still in those.