With mine when they were younger we'd just set a schedule but with twins it only really works if both sleep at the same time. And then they started teething and didn't want to nap but the other did and it got really difficult, but if you just make sure they get enough sleep and stick to the schedule as much as possible, such as putting them down at nap time, closing the door, but if they get up don't fuss. And then at night put them down at the same time as always (trying not to make it any earlier) and of course make sure they know, it's bedtime. But if they go to early you run the risk of a 4:30am wake up call.