Summarize this article:

Knowing what you do and do not want to do is essential to developing confidence and assertiveness. Think about the things you do for others that make you feel used, and write them down. You may be taken advantage of more than you think.  For example, if you always pick up the check, put it in the "to don't" list. Ask your friend to pick it up next time. Organizing information in list form and checking it off hits our information processing sweet spot. This list will be easy to follow and satisfying to fulfill. If the thought of confronting high-pressure situations makes you sick, start small. You may not be able to stand up to your bully right away, but you can make little changes to build your assertiveness. If you ordered a salad but received a soup, send it back. Once you start getting comfortable with asserting yourself in small situations like this, start building up to bigger ones. If you expect you are going to fail, you have already accepted failure. Base your expectations on what you would love to see happen, not what bad thing you are expecting to happen. If you have done all you can to correct the situation, get out of it. Try to remove yourself as much as possible from the person who is trying to take advantage of you. Life is too short for you to put up with someone who disrespects you. Make the brave choice and remove this person from your life. Keeping them in your life will do nothing but maintain the negativity and you will find it harder to grow confident.

Summary:
Create a “to don’t” list. Pick your battles. Expect the best. Cut out the negativity.