This may not apply to everyone - especially depending on insurance. But when I had DD1 in the hospital, I had to pay everything out of pocket, so I really looked through the bill the hospital sent.
I'm sure they just push a button and a list of standard services get itemized.
I declined a lot of things - pit, Hep B shot, etc. - and found several items on my bill that should not have been on there. I was able to remove them save a little bit of money.