Mistake 6: Raising your voice
Look, at some point, your child will do something suboptimal. Perhaps throw her drink at the person's head in the seat in front of you. Maybe run down the aisle screaming Italian swears. Maybe she'll realize she's on a weird flying car and has been for several hours and missed her nap and she'll decide this is some end-of-days shit. Whatever the case, we've all been around babies yowling or shrieking on a plane. People are used to that. It happens. What people aren't used to, is when it's a parent throwing the tantrum.
I've been on planes where a parent lost it and screamed at their child, and it's infinitely more uncomfortable and embarrassing and unnerving than a baby crying. So even if your child has somehow managed to rip off a priest's toupee and wave it around while attempting to unlatch the emergency exit doors at 35,000ft, be cool. You can be stern and decisive without the yelling.
If everything else fails, download Sesame Street on your phone, hand it to your child, slump in your seat, order a gin & tonic, and accept defeat to the soothing sounds of Super Grover, Cookie Monster, and Murray Has a Little Lamb. The plane has to land sometime.