1. Mind your own business.
Ex. 1: Child doesn't want to play soccer/read classic English novel/learn piano/do the thing his parents wish they had done and have now decided to inflict on child. Solution? Parent, mind your own business.
Ex. 2: Child: "Mom, (insert sibling name here)
2. Get off your butt.
Ex. 1: Child is doing some annoying thing and won't stop when parent says, "Stop doing that annoying thing!" Solution? Get off your butt. Armchair parents, like armchair quarterbacks, never go to the Super Bowl.
Ex. 2: Child yells, "Will you get me some milk?" Solution? Is child sick or injured or 14 months old? Then child needs to get off his butt. Same answer applies for "Mom, I'm hungry," "Mom, I'm cold," "Mom, I can't find my shoes," and "Mom, I spilled water all over the bathroom floor."
3. Suck it up.
Ex. 1: Parent: "My child is intense/sensitive/introverted/extroverted/stubborn/slow to warm up/whatever other temperamental trait annoys you." Solution? Suck it up. You get what you get. Stop whining about it, stop "putting the I wish above the It is," and suck it up.
Ex. 2: Parent is afraid little Johnny may be forever scarred by mom having a life away from Johnny, by finding out that he isn't the smartest or funniest or fastest, by not winning a trophy, by not getting all the things he wanted for Christmas, or by hearing "no." Solution? Johnny will have to suck it up.
I really think that these rules might be the fundamental ones for all human interaction, but so far, I have only applied them to parenting. I'm pretty sure they would work just as well in romance, friendship, and the workplace.