Worst for me was definitely "enjoy the sleep while you can" when I was 40 weeks pregnant, not sleeping well anyway and desperate to meet my baby.
Also, not to introduce a bottle until 6 weeks plus (even expressed milk), in case it interfered with breastfeeding. We waited, then baby flatly refused to ever take a bottle so all the nights were down to me and I couldn't get any proper time to myself for the first six months really.
Also, everyone said "don't bother with a birth plan it all goes out the window".. while it's true your birth doesn't go up any sort of plan, and mine certainly didn't, going through the process of talking through your preferences with your birthing partner and what's really important to you is really helpful.
Best - that it's totally normal to cry all day on day 3. I didn't even know this was a thing until someone from NCT said it, and my goodness it hit me badly.
Another best - you can never have enough muslin cloths, and make sure you get a range of sizes.
Advice I would give (if asked for, I've had my fill of unsolicited advice ):
- nappy bins are so cheap because they make their money on the refills
- dresses aren't practical on babies that can't walk yet, they ride up and get in the way
- a next to me / snuzpod / crib with the side down attached to the bed is a must have
Any others?