From Dale Carnegie's "How to Win Friends and Influence People"
People react very badly to criticism; don't do it, not to their face nor behind their back ... especially not behind their back.
Express appreciation. People yearn, yearn to be appreciated.
"Arouse in others an eager want." Corollary: let others take credit for your ideas; they'll like your ideas a lot more if they believe them to be their own.
Ways to make people like you
Greet everyone you meet and show an interest in them. Remember the things that are important to them.
Remember it, use it when talking to them. A person's name sounds beautiful to them.
Encourage them to talk about themselves and their interests.
Strain to find out what that is and recognize their importance. Talk to people about themselves and they will listen to you for hours.
Give in! Agree that the other person is right; often they are and if they aren't, you'll never convince them of it by arguing.
They may be but telling them so is always counterproductive. It is difficult for a person to admit to themselves that they are wrong; harder still to admit it to others.
Openly and freely admit whenever you're wrong. And always leave open the possibility that you're wrong even of you think you aren't.
Always begin that way. Don't accuse.
Look for ways to do or say something nice.
When a person has said "no" it's hard to get them to change even if they know they're wrong.
Listen patiently and don't interrupt. Let your friends be better than you.
First, tell me what you expect of me; then tell me what I can expect of you. People will generally live up to the commitments they make to you as long as they came up with them on their own.
Where they stand depends on where they sit; figure out where they're sitting.
Give it to them and they will love you.
"Don't use logic; tell stories." Make your ideas visible, concrete. Bear in mind that people don't know until you show them what you mean.
Be indirect in your criticism. Praise before you condemn.