Couple things I find true. You can't control when they finally are tired enough to fall asleep, but you can control when they wake up. So I change the time I wake them up to adjust their schedules.

And restful sleep at night. With one of my kids, I would let him sleep solid for the beginning of naptime but would go in his and stir him up in intervals to make sure he slept through the night. I was so frustrated that he could take a four hour nap without waking up but couldn't sleep fours at time during the night... Well I fixed that.

Most toddlers need about five hours between nap and bed, so figure out how much time your kiddo needs and then wake him up accordingly from his nap.