Jump right in. Playtime with a caregiver is invaluable to a child - whether you talk baby-talk or bounce a toddler on your knee.

Forget the rules. Add to a child’s play experiences by creating imaginative games and finding new ways to use his toys. Use blocks as flying cars or pretend to be a zoo animal. Encourage a child to make-believe and think creatively.

Take a break. Although children often learn the most when they interact with others, solitary play gives a child time to process and understand everything that he has been doing.

Participate enthusiastically. Encourage a child’s imagination by becoming involved wholeheartedly and going along with her games.

Let a child guide his play.
Let a child pick the activity and decide how it is played. Pay attention to the child’s mood and adapt the play accordingly.

Watch out for over-stimulation. It’s important to stop playing when your baby loses interest. He’ll tell you when he’s had enough by disengaging, turning his head, or starting to cry.

Source: http://www.bornlearning.org