4mth old sleep routine. Where, when and how long in 24hr?

[TwistTee]

Up to now ds sleeps when he wants and mainly falls asleep after a feed in my arms or in the car if we are out.
He is currently going through hourly waking up at night which may be the 4 mth sleep regression (I had not heard of this until yesterday) and may also be teething.
I have decided to try and get him into some sort of routine but have no idea what's best. His sister, 4, goes to bed at 7.30pm, so 7.45 would be good, but then what about naps? How long does he need at this age?
Any tips on putting him down to sleep awake?

I forgot to say, for naps, he sleeps on a mat on the floor or in his car seat, but neither seem to last long at the moment.

Hi. My LO is 4 months old and on average has 3 naps a day, totalling 5 hours. Having a routine doesn't mean each day is the same as somedays go completely out the window. He goes down at 8 at night and gets up around 6.30. In between this time he will either be good as gold and just wake for his feeds (normally 12 and 5) times vary. Or like now, he is waking every hour so I'm just dealing with it.
Once he's awake in the morning the aim is to not go done for a nap until around 8, he will sleep for around 1.5hrs. Next nap around midday again 1.5hr then later nap around 4. Sometimes he will fight this nap and want to stay awake and then shattered by bed so I try and get him to have at least an hour even if its at 6pm. Then bed routine at 7.30 and in bed for 8. Nap times vary but normally a gap of 2 hours between waking and going down for next nap. Generally at this age 5 hours day sleep and 10 hours night sleep. I know it's not always easy to get that. I just try and keep persistent as he will fight it if i put him down over tired but eventually he gives. I've learnt if he cries when he's asleep he's not wanting to be awake so I pop him dummy back in and he goes off. If he wakes up chatting then he's had what he needs. Hope this helps xx

I might add that all naps are In the cot unless we are out and it's in his car seat.

OP I'm so jealous of you! DS 3.5 months used to sleep anywhere - make the most of it! he now will only sleep in his (moving) pram or (moving) car and even that is by no means guaranteed. Trying to get him to nap at home when he's tired can mean up to 2 hours screaming (even in my arms, rocking and shushing). He almost never sleeps longer than 45 minutes at a time either, usually less, outside of the hours 10 to 7ish when he'll sleep 3-6 hours at a time.