Talk about your own mistakes before criticising the other person.
A person's toothache means more to that person than a famine in China which kills a million people.
Think and Thank. Think of all we have to be grateful for, and thank God for all our boons and bounties.
Nobody kicks a dead dog.
Tell your child, your spouse, or your employee that he or she is stupid or dumb at a certain thing, has no gift for it, and is doing it all wrong, and you have destroyed almost every incentive to try to improve.
Take charge of your attitude. Don't let someone else choose it for you.