Method 1: When you are in a bad mood, consciously change the subject, or do something else, such as listening to music, watching TV, playing ball, playing chess, walking and so on. To distract yourself and ease your mood.
Method 2: Telling your troubles to your relatives or close friends or even crying, or venting accumulated troubles by throwing pillows and punching sandbags will also be beneficial to your physical and mental health. However, you should pay attention to the object, place and occasion of venting; Methods should also be appropriate to avoid hurting others.
Method 3: When you want something, or you fail to do something, in order to reduce your inner disappointment, you can find a suitable reason to comfort yourself, which can help you accept the reality and maintain a more optimistic attitude in the face of setbacks.
So the answer is: divert attention; Vent; Comfort yourself.