Just wanted to say that this is what I've learned from experience
1. Don't ever put yourself down or make yourself look pathetic like speaking ill of yourself. The way you treat yourself is how to show others how far they can treat you.
2. REMEMBER who you are. Remember the things you love about yourself and hold yourself to a high standard. Don't let anyone get a reaction out of you that you'll regret later. Also don't bend too much or be too eager to mould yourself to suit someone else.
3. Don't put up with abuse or bullshit because if you do, they just feel that if they got away with it once they can do so again and then the cycle of disrespect begins.
4. Make sure you have a life and interests outside your significant other. It's healthy and also makes you appear more self reliant and independent and therefore more desirable.
5. Seeing yourself from a 3rd person perspective helps when making tough relationship decisions, or just deciding how to react in general. If you were someone else, you think reacting in a certain way makes you a good person/sensible/mature? Or would you cringe at such a course of action? Helps make decisions.