The establishment of routines can help your baby to sleep at nap time, too.
After feeding the baby, avoid that he or she fall sleep in your arms, for example, changing his or her diaper or reading a short story.
Place the baby awake but drowsy in the crib and set the mood to ease him or her to get asleep.
If you do all these things more or less at the same time each day, it will be easier for the baby to know that it is nap time.
Of course, it is inevitable that sometimes we have to do an exception, but this wouldn’t harm your baby