I think we started when DD was getting on for three months - you know, no longer tiny tiny and going for roundabout the same time between feeds.
We started doing bath, then feed, then into sleeping bag and in moses basket at our feet in the sitting room (while we watched TV). She would suck her dummy, watch us, and gradually drop off to sleep. We'd have to do it this way as at three months there was no way she would happily lie in a moses basket on her own out of sight of us.
She'd then wake about 11 for another feed (when we went to bed) and we would put her moses basket inside her cot, which was next to us. So she would sleep there, then wake up around 3 or 4 for another feed, then morning.
In the morning we would have a feed in bed then get up, put day clothes on etc.
A bit later on, say 5 months, we started to put her straight down in her cot in our room after her bath and feed, and then we would be downstairs with the baby monitor.
About 7 months, we moved the cot into another room.
I think its just very gradual steps, as they get older more of a pattern emerges, you can expect more of them.