Totally agree with first para of lapin's post - bedtime routine signalling 'this is bedtime, long sleep now', structuring the rest of the day around this and of course making allowances in the early months for feeding/growth spurts/teething, is a great way of getting the baby to fall into a feasible routine.
Of course, it will take a little time to establish, and there will be days when it doesn't work, but babies aren't machines and more-often-than-not is pretty good for a good few months after birth.
We did this from day 5 of DD's life, and she has never (not once) not fallen asleep for a good long stint (5 hours +) when put down for the night. I mix fed.
However, you might want to think about why you are looking for a routine, something you possibly decided you wanted during pregnancy given you are concerned about establishing it so soon after delivery.
Is it for the baby's well-being? I am not qualified to say whether babies need routine or not, I don't think there is a right answer to this, but I suspect your child will lead you to the right answer for him, which you may just have to live with.
Or is it for you/your family? It was for me, and the best thing I did once DD arrived was to relax about it all. I had been very keen to ensure that the rest of us continued to lead normal lives, that the house continued to run smoothly, that we were all well fed, and that we continued to see our friends and family etc. I thought routine would be the key to having this. However, I very quickly found that the routine was ruling me, instead of serving me, and life became so much easier when I started going with the flow a little. I began to adjust things here and there (call them compromises, if you will, some that DD made, most that we made) and now, several months down the line, we have all the above and DD is a happy, healthy, thriving young child.
So, my advice would be to ensure that the routine you decide to establish serves you, rather than enslaves you.
Congratulations, and good luck!