Encourage tummy time: Since babies spend all night on their backs (to reduce the risk of Sudden Infant Death Syndrome) it's important to put them face down during the day, while you are closely supervising them. This "tummy time" will help them develop their neck and upper body muscles.
Stimulate rolling over: Babies usually roll over somewhere between 4 and 6 months of age, but you can start encouraging her to roll over before then. Try lying baby on her side on your lap and then putting a toy a few inches away, says Wallace. Make sure her arms are free so that she can roll without having them pinned to her side. Another method: lie baby on an activity mat with one arm straight down by her side. Then roll her over on that side.
Develop body awareness: Help baby develop awareness of her hands by singing "Pat-A-Cake," "The Itsy Bitsy Spider" or other songs that involve hand movements (you can make them up too). Don't forget to get baby's feet involved. Sock rattles can also help her become aware of her feet. Babies at this age are also beginning to develop recognition of facial characteristics, so keep pointing out facial features in the mirror. Some parents use flash cards with features pictured and labeled. And take advantage of bath-time fun to help baby label body parts too.
Sound identification: Record the sounds of normal activities — a dog barking, a door opening, footsteps — and play them back for baby while explaining what they are, suggests Wallace. Baby will also probably get a kick out of hearing his own laughter played back. A hand-held tape recorder is ideal for this purpose.