Remove distractions. Although babies may understand being tired, they don't understand the concept of sleep. They drift into sleep like adults in a boring lecture. Your tiredness routein should focus on settling baby down and excluding harsh distractions. A little light can help baby be aware of their comfort place; soft background noise from a fan or radio turned low. Put them down awake & don't change anythiing.
Routine. 4- 6 months is a good time to develop a bedtime routine. Your baby will learn to expect the routine quickly. For example, a feeding, a bath, change into pjs and rocking until drowsy. Make sure that you put the baby in the crib while he/she is drowsy but awake enough to remember! this will help your baby to sleep all night on his/her own.