4. Be firm:
Some people can be convincing and persuasive in an attempt of taking advantage of you. You have to be firm and stick by your decision. Do not allow them to sway you, no matter how convincing they sound. Learn to be firm and believe in yourself.
Basically, you need to identify people who try to take advantage of you and stop them before it becomes habit. Remember, you are in charge of your own happiness. Do not make other people a priority in your life while you abandon your own needs!