Try to think about happy things. When people are sad, when we are sad, we try our best to think about the happy things before. We will forget our troubles for a while. As long as we pass this threshold, we will not be so sad.
Do more. When you are sad, find something to do and turn your attention away. Then you will forget the unhappiness for a while.
Chat with friends. Find friends to chat, talk about your sadness with friends, and then find a solution with friends. After the solution, we won't be so sad.
Watch comedy. There are many funny places in comedy movies or TV. Maybe we'll get better after watching them.
Sing. At home or go to the concert hall to sing and vent. After venting, the burden on you will be reduced.
Enjoy the sadness. Sometimes we can think that ups and downs are the necessary subjects in our life. How can we show happiness without pain? Life without sadness is incomplete. Why not enjoy sadness.