My DS is 4 months. Being a first time mum I thought I would just do my own thing and see how that goes. We don't really have a routine. The only thing I am doing is trying to get DS to sleep through the night which is working so far so good. I tend to work off feeds. He has his dinner every 4 hours pretty much on the dot. So this is what usually happens with him:

7am - Wakes up and eats. He then will stay up for about an hour or so.
He will then sleep till about 10 - 11am. If he wakes up at 10 - he is fine to just do his own this till about 11 which is feed time. He might then stay up for 1 1/2 hours to 2 hours. Then sleep. He'll wake up between 2- 3pm for his feed. Next feed he will get up around 6-7pm. Then at 10pm I will get him up regardless of how long he has slept (sometimes 1 - 1.5 hr). He then stays up till about 11 -11.30pm and then he sleeps through. I would prefer to go to bed earlier but then again who am I to complain when I am getting an 8 hour sleep??

I really don't mind what goes on in the day and if he wants to stay up, it's fine with me. The only time I intervene is at nighttime where I make it work for me. Lucky DS is a good boy and does what mummy says!! lol (for now anyways..he'll probably be a right little terror when he starts getting around on his own.)

So I guess - whatever works for you - do that.