Hi, there. You have asked a good question. Baby skin, especially newborn skin, is very sensitive. One should be careful what uses. Usually water is enough, but from time to time a little amount of soap can be used. Soaps should be mild. They can contain coconut, olive or palm oil. There can be herbal extracts like calendula. Pediatricians recommend avoiding antibacterial soaps. After bathing, you can use some body lotion containing saturated oils. Those would be coconut or sesame, even herbs like calendula or arnica. Some babies are sensitive to this, so you should be careful.