We started with a preferred wake up time at 3.5 months. We then fell into a bit of a pattern based on her wake windows and nap lengths. Feeds were done when showing hunger signs and naps when tired. Bedtime moved from 10pm to 8pm then naturally she wanted earlier. I'd schedule anything round her naps to start and bottle feed out if needed. I personally needed a sort of structure to the day but it still worked on what she needed and when. You'll need to adjust it with time based on longer wake time etc so I think it's still important to follow their cues. Good luck!
Tbh my baby is just falling into her own little routine, I haven't done anything to encourage it x
Tbh I started with a bedtime routine and the rest kind of just fell into place with mine