It’s hard to entertain them especially in the late afternoons I found as all the classes and things to do seem to be on in the mornings.
What I do is make sure we get up at the same time every day and that way the days fall into a pattern.
Up say 730 and then milk breakfast etc play, then I would try and have a couple of days with a class or a group to get you out by a certain time.
I loosely followed Gina ford’s timetables (never read the books just her timetables by age) which gave a framework for feeding and naps and I worked around that. Get out for walks, do shopping, have “activity stations” around the house to give a change of scenery when they get bored, find the best way for them to sleep during the day (pram, car, cot, your arms) and make sure they get that sleep even if they fight it.
Then get a bedtime routine starting early and aim for bedtime lights out around 7 or 730 latest.
The key (perhaps not obvious) thing with a routine tho is you need to do it every day and stick to it, even at weekends. Might suck getting up early if that’s not you but you’ll see the benefits long term.