a) Avoid thinking about unnecessary things specially related to others. Mind your own business. Posses a focused mind.
b) Stop comparing yourself to others. It's an insult to yourself. You are a unique soul and you are independent on your living, your decisions and your destiny.
c) Don't think of monetary gains too much. Excessive love for money and assets is the root of most of stresses. Work on your real wealth.
d) Develop the habit of forgiving and letting things go off. If you are keeping the grudge in your brains for longer durations, you are killing yourself. Stress is a slow poison which deepens its roots your brain and destroy your physical and mental health.
e) Read quality quotes or articles on positivity and try to absorb the message. This will kill the germs of negativity.
f) Practice the habit of gratitude. Stop complaining, criticizing and blaming. When a negative thought comes in, convert it to positive by looking at the positive side of the issue.