Keep your bedtime routine relatively short (30 minutes max) and make sure that it is consistent and calming. You should do the same sequence of events every night, in the same location and under the same conditions. Babies with a well designed consistent bedtime routine sleep longer and better with fewer night wakings.
Try to put your baby down for naps at the same time every day. You should also have a mini routine for naps that only lasts for about 5-10 minutes. The same principles apply as for the bedtime routine.
This means making sure that your baby continues to sleep on his or her back and is not in danger of becoming entwined in the bedding. Make sure that your baby is kept at a temperature that is neither too hot nor too cold.
This means not nursing your baby to sleep, rocking your baby to sleep, using a pacifier until sleep, driving around the block with your baby in the car etc. You can use these devices but stop before your baby falls asleep or you will have created a sleep crutch that is hard to break and you will almost certainly have problems with night wakings further down the road.
When your baby wakes in the night, try and wait for a couple of minutes before rushing to his or her assistance. Obviously, if your baby sounds very distressed to attend immediately but otherwise, give him or her a chance to self-soothe and fall asleep on his her own.
An overtired baby will not sleep as well and will have more night wakings.