Some people are all for routines and some are completely against them. Personally, I've found having a routine made life so much easier. TBH we sort of fell into one which was based on the feed, play, sleep recommendation. In the early days DS would feed for about 45 mins, I'd have a play with him for 15 or 20 mins and then it was back to sleep, for however long he slept. Generally though he was feeding every three hours. At the end of the day we would do bath time instead of a play which I think meant he quickly worked out that bathtime meant it was night time and time for a long sleep iykwim.

Personally I'm not one for set times, we get up at this time and you get fed at this time kind of thin, but I think it if you start having a pattern to your day then a routine quickly emerges which might vary by an hour of so each day, but it makes it much easier for you to plan and also easier for bubs because they know what's going on iykwim.

Anyway, hope this helps.