I have a few I want to share:
1. Everyone is normal till you get to know them. (Meaning you are no better than anyone else, nor they you)
2. Be the first to smile.
3. Read, Learn, and always keep an open mind, which will allow you to be secure in your convictions.
4. Whatever energy you put out, positive or negative, you'll receive multiple.
Shalom
1. Close to your #3 - Engage with people and information sources that have different perspectives and views than your own. It's close to impossible to grow, truly embrace your beliefs, or understand others without doing this.
2. Look at your priorities and goals, the ones that are reflected in what you are actually doing and pursuing and ask yourself if you're really going to be satisfied with the probable results as the end of your life nears.
3. There's no excuse for treating others badly. There's nothing cool or respectable about being an ahole; it just shows that you're insecure and lack character.
4. Accept the fact that over the course of your life you will have to do some things you don't want to do and make some sacrifices to have the things you want in the long run. This is true in learning, relationships, professional pursuits, and many things that you will want to do for pleasure. (For example, you can't become proficient at playing a musical instrument without slogging through the early stages when you aren't very good and the sounds you make are awful.)