-Thank the advice-giver for their input and drop it. This is a classic, and in
-Drop the “Dr-bomb”. Older relatives especially may have outdated information, like starting solids too soon or covering babies with blankets while sleeping. If you don’t want to argue, throw your doctor/midwife/pediatrician under the bus. “That’s what I was going to do, but the pediatrician says…” If they tell you that the doctor is wrong, just shrug and nod and keep doing what you’re doing.
-Be straightforward. If you’ve made up your mind, you can always let them know that. “Thanks for your input, but we’re going to…” or “I looked into it pretty well, and we’ve decided…”
-Clarify the situation. In some cases, people don’t need to know why things are different for you, but if it’s a close friend or relative, you might want to share why you’re doing things “wrong”. A quick, general explanation can often stop even a persistent adviser. "Since I have gestational diabetes, that's not true for me." or “I’m sure that’s true for most children, but since we (special circumstance), we need to...."
-Have a teaching moment. This is probably the trickiest, but it can really get the job done. If you can back up what you’re doing with some science or experience, you can turn a bad-advice-giver into one who may at least share good info with others. “Infants over 6 months feel temperature the same way we do – so really, if I don’t need a jacket, hat and scarf, neither does she. Over dressing babies can make them too hot and actually lead to other problems.”
Remember, most people giving advice really do want to help. The best advice we’ve ever heard for new moms is to take the advice that sounds good to you and throw the rest out. Find a few trusted sources and let the rest roll off your back. You’ll figure it out – we all do! Most importantly, enjoy that baby!