I'm currently co-sleeping with my dd (9 months) in that she's in her cot, with side down, next to our bed and regularly sleeps with us in bed normally after a breastfeed as we've both fallen back to sleep
I started a bit of a pattern (dislike the word 'routine'
) at around 11 weeks & it was because we were on holiday and wanted a little time to ourselves in the evening.
As she was sleeping from 7pm either on me or in the Moses basket downstairs, we decided to start a night time bath, story and lying down on our bed for a feed pattern and let her get sleepy (or fall asleep) and then popped her in the Moses basket in our bedroom. Every night on holiday she slept from 7ish till 10.30/11 and that started our pattern off as it was the best she'd slept since she was born.
So when we got back, we continued to do bath, milk, story, sleep in our room. We went from Moses basket to travel cot to big cot as she got bigger.
I was never too bothered if she fell asleep on me or not, but dp and I decided, once she'd have a bath, she'd stop upstairs with one of us until asleep and it was fairly quiet, relaxed, dim lights etc.
Within a week or two she got used to it and we were both back downstairs eating our dinners by 7.30/8pm.
I struggled massively with her being upstairs at first - I kept checking on her and felt a bit lost, but when we went to bed, she'd be right next to me (or with me once she woke up for her many nighttime feeds, and we'd fall back to sleep together)
She also got used to dropping off in her own bed as opposed to on me, something which my other co-sleeping friends have struggled with. She still does fall asleep on me sometimes but mostly I can put her down for her nap or bed awake/sleepy and she will go off on her own without crying or grumbling.
Dp and I still don't haves set bed "time" (or nap times" but roughly she's in bed by 8pm every night.
Now however I'm about to embark on moving her in to her own room as I think that we dp and his snoring are waking her at night, which in turn means me feeding her back to sleep and we've now reached a point whereby I'll try something different to see if it helps her sleep better. I'm under no illusion that she still needs a night time feed, but one every hour from 11pm til 6pm is getting a bit too much 
Sorry for the long post, hopefully sharing my pattern is useful to you 