Pretty powerful: A familiar smell like yours can help your baby cope with unpleasant experiences (like those mandatory heel sticks). Nursing? Don't feel bad that you didn't get to shower again; breastfed 2-week-olds can recognize their moms by armpit smell alone!
Oh, baby! Smelly stuff your infant will love:
Soothing baths. Using a baby-safe bedtime wash that contains natural ingredients like lavender -- Aveeno Baby's Calming Comfort Baby Bath is a good one -- can help soothe and reassure a fussy infant.
Smell-good friends. Eden's Sherberts Collection
Your natural scent. Attach your scent to a burp cloth or blanket by sleeping with it for a few days. Then place it near your baby while she falls asleep to help her relax (then remove it).