Be conscious of your thoughts each minute as if your life depends on that thought. Someone once said, thoughts have a tendency of clothing themselves in their physical equivalent.
Imagine thoughts as chemicals in the lab. They are mixed every time, every moment, every second. The products are always exactly from the chemicals. If you mix chemicals of joy and happiness, it translates to its physical equivalent. You become happy and as a bonus, you meet and will always be with joyful and happy people.
Moreover, learn the skill to drive your thoughts with courage and faith. Misuse of thoughts can be suicidal. Be of good courage and cheer.