Build a positive attitude

First of all, never ever compare yourself to others; Before thinking about others good qualities, think about your good qualities and improve them.

Second, believe that everything is possible; but you have to try hard. Set your goal, and work hard to reach it.

Third, if you think that you haven't enough of something in your life; make a goal to get enough of it.

Fourth, give everything a chance before you neglect or reject it. It may be the reason for your happiness.

Fifth, grooming; appearance effects you; stay natural.

Sixth, communicate your needs; if someone make you feel down, just say to him/her.

Seventh, stay upbeat; don't let people sayings let you down; it's just their personal opinion.

Eighth,  do whatever makes you happy and it's not harmful.

Ninth, smile; always remember to keep a beautiful smile on your face, whatever is going on. 

Taken from: WikiHow