The best thing my parents did was be consistent. Early on I learned how to behave because I could predict my parent's reactions. How can a child learn to behave when all adult figures are erratic and irrational? Even the smallest things, like telling a kid Santa Claus is real can cause them to discount the value of truth.
Reading behavioral psychology studies should require a skeptics hat. I'm not calling out these specific studies, but when it comes to miniscule sample sizes, unreproducible and sometimes out right made up results, this area is very suspect due to ease of fudging results. (Diederik Stapel comes to mind as an extreme case.)
The famous "marshmallow experiment" is great evidence for this. When the original experiment was re-analyzed, researchers found that children from stable, consistent environments, with reliable trustworthy adults, were better able to withold temptation and show patience to win a "2 marshmallow" delayed reward in exchange for a sacrifice of "1 marshmallow" now.
As soon as he was old enough to understand, I showed my kid the marshmallow experiment and taught him a few ways to mess with the experimenter, if someone were to try this on him. Bwahaha.
For comparison's sake, it's neat to look at the psychological outcomes for children of alcoholics (where the element of consistency and predictability gets thrown right out the window). I realize that I'm a single anecdotal piece of data, but the good news is that therapy can help get over it :).
Reading behavioral psychology studies should require a skeptics hat. I'm not calling out these specific studies, but when it comes to miniscule sample sizes, unreproducible and sometimes out right made up results, this area is very suspect due to ease of fudging results. (Diederik Stapel comes to mind as an extreme case.)