Lower the lights
Because your infant's been in the dark for nine months, harsh lighting can be uncomfortable, so keep your rooms dim. The low light will also help her to focus on things within her range of vision, which will be only about 8 to 15 inches away from her face at first. Eventually she'll need to learn to distinguish night from day (if you're aiming to get her on a normal sleep schedule), so don't turn on the lights when she needs wee-hour feedings and diaper changes; a nightlight will do.
Warm her up
It's hard for your baby to keep her little body warm. To take off the chill, put one more layer on her than you have on yourself -- add a T-shirt or one-piece suit, or a cotton blanket. But be careful not to overbundle her and don't crank up the heat: A baby who's too warm may get sleepy and not feed well.
Your newborn now has more space to move her arms and legs around, but those movements can trigger her startle reflex -- a normal flailing of the limbs. (This reflex also kicks in as a response to a loud noise or the sensation of falling.) Try wrapping your baby in a receiving blanket to mimic the tight space of the womb until she's about 2 weeks old; after that she'll need to be able to flex her little muscles to strengthen them and develop coordination.
Get her body in motion
She's been moving right along with you since conception, so it makes sense that rocking will give her a sense of comfort and security. Cradles, swings, strollers, and front carriers will all do the trick, though nothing can beat swaying to a lullaby in Mommy's arms.
Don't turn down the volume
Your baby's gotten used to the noisy world of the womb, so regular house sounds, like the vacuum, the clink of dishes being washed, or just the familiar sound of your voice reading aloud or whispering sweet nothings into her ear, will help her feel right at home.