1. Lying
What about white lies? If you are tempted to lie in order to protect someone's feelings, consider that assertive communication goes a long way, since many white lies are based on opinions, not facts. If someone asks “Does this dress make me look fat?” any response that you give is just your opinion, so there is no need to be offensive. You can choose to respond assertively in a way which protects someone's feelings, such as, “I think the other dress is the most flattering, but that is just my opinion.”