7 ways to cultivate a positive mental attitude

1-Control your thoughts and emotions

Try to feel as often as these positive emotions: 
Joy– It is a perfect moment captured exactly as it should be.
Gratitude When you are thankful for someone that helped you, and you want to do something in return.
Serenity the state of calm, peaceful, and untroubled.
Hope- Unlike the other emotions that arise in comfort, hope arises from the bad circumstances to give you strength to move forward.
Amusement-think amusement as those unexpected moments that interrupt your focus and crack you.
Love- The most important and powerful emotion. When we experience love our body is filled with feel-good emotions. That can reduce stress and lengthen our lives.
Other powerful emotions include pride, inspiration, awe, enthusiasm.
You should avoid these negative emotions: Fear, jealousy, hatred, revenge, greed, superstition, and anger.
2-Never get even with your enemies
When we hate our enemies, we are giving the power over our sleep, our appetites, our health, our happiness. Our hate is not hurting them, but our hate is hurting us. Never waste a minute thinking about people we don’t like.
Don’t worry about ingratitude, expect it. Jesus healed ten lepers in one day, and only one thanked him. Should you expect more gratitude than Jesus got?
4-Count your blessings, not your troubles
Always count your blessing, no matter how bad the situation might seem there is always something you could thank God for it: Family, health, friends, your strong faith in God.
Remember these sentences:
I had the blues because I had no shoes until upon the street
I meet a man who had no feet.
5-Be yourself
Don’t try to be like someone else. Of course, we all have idols that we wish to be as successful as they are. Maybe you can, but don’t compare yourself with someone that you think is better than you. That will low your self-esteem. Don’t compare yourself with your brother if he is good at sports and you aren’t. Don’t compare yourself with a classmate that has better grades than you.
No matter how successful you can become, there is always someone better than you. If you make 10M$ per year you can meet someone that is making 20M$ per year. Don’t compare yourself with others.
You don’t have to feel inferior or superior toward someone else.
Everyone is special human being, all of us have good points and bad points of our character.

6-If you have a lemon, make a lemonade

A wonderful sentence from Dale Carnegie. If life gives you hard times, temporary defeat(because every defeat is temporary), a misfortune or difficulties say:
What lesson can I learn from this misfortune? 
How can I improve my situation? 
How can I turn this lemon into a lemonade?

7-Be generous

Let’s forget our own unhappiness, by trying to create a little happiness for others. A good deed said Prophet Mohammad” is one that brings a smile of joy to the face of another”. 

Source: “How to stop worrying and start living”, by Dale Carnegie.