Practice speaking in a kind way. For one day, keep every negative thought, frustration or complaint to yourself and only share your positive comments with others. And every time you do have a negative thought, counter it out loud with a positive one. See the silver lining in the cloud in every situation.
The more you practice this, the better you will feel. You will have less negative thoughts in general and you will become a positive influence to all those around you. People will love being around you and will seek to spend more time with you.
Don't stop at one day! Try this for a whole week. And then for another, until it is second nature. Share your new secret to positive thoughts with your friends and family and encourage them to try it out, too!
Think of one situation or thing in your life right now that is causing you stress. Make a promise to yourself to stop thinking negatively about it, and to find the positive possibilities in the situation.
Read more about the power of positive thinking.