I think do whatever works naturally for you, but don't try to force it if it isn't coming just yet. At 9 days, we definitely didn't have any sort of routine of any kind. In fact, I wasn't always sure if it was day or night because it all just blended together. Probably around 2 weeks or so, we started to have more of a routine, in the sense of a feed around roughly the same time in the early evening and then my daughter would go to sleep on daddy's chest or with him in the wrap until her next feed around 10 or 11pm. And I would go to bed to get some sleep before I had to feed her again! That was our routine. She had a bath maybe every 3 days or so, usually late in the afternoon, before her feed, but there was really no routine to it. We didn't start a proper bedtime routine with her until about 3-4 months. Once we did, it was bath, reading a book, milk and then I'd lie down next to her while she went to sleep. But that was really only after she'd fallen into a routine on her own. I think if you find it helps and just happens and it works for you, do it. If you have to force it to happen still, just wait a bit. Our daughter who had no bedtime routine at all easily transitioned into one and went to bed easily when she was ready. Until then, she slept on us while we ate dinner and watched tv and we all went to bed when we were ready. As you have an older one already, you might find that things naturally fit around the routine you already have when the time comes.