There's one very important thing that all new moms have in common: They're new moms.
That's just about where the similarities start and end. Some will be blissed out with their itty-bitty bambinos, while others will be stressed out with the (lack of) sleeping and breastfeeding. No mom recovers like another after giving birth; likewise, no two babies are exactly alike.
And yet most of the advice out there is one-size-fits all (not to mention lots of it is just plain bad or wrong). New moms are often tired, overwhelmed and apprehensive, and getting advice from others can burden them more than it can lighten their already-heavy load.
While your advice is probably spot-on (after all, look at your happy, smart and funny kid!), these gems need to be permanently (and immediately) retired:
"Sleep when the baby sleeps."
"Enjoy every minute."
"Don't spoil the baby."
"Keep the baby up during the day to make sure they sleep at night."
"It gets better."
"Don't wish the time away."
Sometimes the best thing you can do for a new mom is to be a sounding board.
The fact is that pretty much the the only advice new moms need from you is this:
STOP GIVING ADVICE.
THEY DON'T NEED IT. (Even if they don't know they don't need it, chances are, they don't.)
THEY ALREADY HAVE ADVICE UP THE WAZOO from their moms, mothers-in-law, sisters, doctors, nurses, midwives, friends, friends-of-friends, neighbors and grocery clerks.
The fact is that unless you're nannying their baby, and therefore know it almost as intimately as its parents, chances are that your children and any new mom's baby will not be soothed/fed/brought to sleep in the same way. Sure, there's a chance, but it's pretty small.
Truly, the single best piece of advice that new moms don't know they need or want is no advice at all. Offer some empathy ("Yeah, this phase can be rough. Hang in there; it will pass.") and tell her you understand. Don't try and solve her new-mom issues, but do offer to listen. Ask if she has someone to watch the baby (or perhaps you be her babysitter for an hour or two?) so you can take her out for a manicure/cup of coffee/glass of wine/walk. Ask if she needs any information or point her in the right direction.
Sometimes the best thing you can do for a new mom is to be a sounding board. Let her tell you how hard it is and how that's surprising for her. She might be spending many hours alone, or at least without someone who can listen and comprehend what she's saying. You're not going to solve all her problems, but just letting her talk might make her feel a little better.
Think of all the advice you were given after you gave birth, and then think about how much of it was actually useful. Then do for others what you would have done for you—which is, more often than not, keeping your mouth shut.