1: Find things to smile at. If you need inspiration, look at a flower or look at the comics.
2: Think about something good. It can be anything good like good food or a good experience.
3: Breathe. Deep breathing gives you extra oxygen to stay positive.
4: Move. Get up for a walk. Take a yoga class. Any kind of movement will help you stay positive.
5: Pray. God gives generously to those who ask and asking to stay positive is a request that won't be ignored.