Being "nice" is a characteristic many people should be instilling in their lives but some people take that niceness to the extreme. There is a difference between being a "nice guy" and a "pushover." Whether you are a guy or a girl, don't be a sucker. Try breaking free of these habits!
Stop worrying about people liking you. With millions of people in the world there are bound to be a few that do not want to interact with you, which is okay. Not everyone is going to like you. Be yourself, be genuine and you will find people that fit into your life.
Don't put the needs of others above your own. Everyone needs a shoulder to lean on from time to time but you don't want someone to take advantage of your kindness. Make sure you are not sacrificing your own happiness to make others happy. Put your needs first!
No one likes a kiss ass. You are not going to gain any respect from others by brown nosing. Mutual respect is a trait of what a good friendship and relationship are based on.
Just like respect, investing in a relationship should be 50/50. If you feel that you are doing all the work in your partnership than you might want to start speaking up.
Don't let your emotions rule you. Take a step back from the situation and use logic to make your decisions. Emotions have crap for brains.
Stop giving people a "free pass." If someone disrespects you tell them. Stand up for yourself by letting them know it is not okay. If they do it again in the future you know that they do not respect you and your feelings.
Understandably, if you mess up an apology is the correct way to go about fixing the situation. Apologizing too often is a problem and avoids the real issue at hand. You only need to apologize for things you did, not what you didn't do.
You don't have to pick up the tab. Just because you invited someone out doesn't mean you have to pay the bill. You might find yourself surrounded by mooches. You do not want friends who only hang out with you because you are always paying.
Keep your power! When you are too enthusiastic about something people will think that you can be bought more easily. When you are too eager about something you automatically give your power to the other person. An example of this can be seen when job hunting.
Self-respect is key to not letting others walk all over you. If you don't have respect for yourself, how will others respect you? You deserve to be treated well!