Get them to bed on time as much as possible
I definitely find if my son get to bed later than normal or too early he has issues with waking up a lot or thinking it's time to play in the middle of the night. I try to get him to bed at the same time every night and I just lay him in the crib and let him get himself off to sleep. He's a little sleep figher but eventually he will drift off.
Also I always try to do things in the same order before he goes to sleep. I feed him, bathe him, read a story and then let him play in his bouncer for a bit to use up some of that last energy before it's bed time.