It's not safe to leave a baby or toddler alone in water, even for a second
Have everything you need in advance - towel, toiletries, clean nappy, clothes. It's not safe to leave a baby or toddler alone in water, even for a second. If you've forgotten something, or if the phone rings, you must take your baby out of the water and wrap her in a towel to keep warm, then take her with you.
Put cold water in the tub first, and then hot. This reduces the chance of scalds. Test the water with your elbow (as hands can bear very high temperatures) before you put your baby in. It should feel comfortably warm.
If your baby's upset, or clearly not enjoying the bath, stop and try again a few days later
You can use a mild soap or a baby bath liquid. No soap is necessary for newborns.
Baby baths are useful, as they can be moved to a warm part of your house, and need much less water than the 'adult' bath. You could use a clean washing-up bowl for a very young baby.
You can take your baby into the 'adult' bath with you, as long as the water isn't too hot, and there's someone around to hand her to you and take her out again.
If your baby has lots of hair, it helps to use a jug to rinse the water through. You can use a mild baby shampoo as it's good for the scalp, but soap will probably be enough until she's older. Be careful not to get the soap/shampoo in your baby's eyes - stinging eyes can put babies off bathtime.
Your baby doesn't need to bath in the first weeks
It's up to you. Your baby doesn't need to bath in the first weeks (see top and tail below), but it can be fun for both of you to do it every couple of days and can be the beginning of setting your baby's routine.
Later on, it can become part of your evening routine - it will help mark the change from daytime to bedtime.
Top and tailing is an alternative to bathing for your very young baby.