After a bedtime routine, If you hold your child until he falls asleep puts you in danger of falling asleep beside him. Try to use the time to meditate, if you can, or listen to music.
If he’s used to falling asleep by holding him, try to touch instead of hold. Eventually, he will be able to fall asleep with you merely holding his hand, or putting your hand on his forehead.
There is also an effective way that often helps kids fall asleep is to give them a giant stuffed animal or pillow to keep at this point, to replace you holding them. Kids usually love to curl around a large, cuddly animal.