Overbathing! One of the most common mistakes i see with babies is over bathing. Baby skin does better with an every other day bath. A luke-warm bath with unscented products is best. Too frequent a bath contributes to eczema, dry skin, and rashes in babies. Less is more. Use of commonly available scented products with dyes is the second most mistake i see in practice.
Using lotions. Parents often use lotions or creams, thinking that the normal flaking skin seen in the weeks after birth needs moisturizing. These lotions and creams, especially scented ones, can cause sensitization and lead to chronic rashes. Another mistake made is forgetting about the creases. Creases of the neck, underarms and groin can get quite dirty and need cleaning several times a day.