Get plenty of sunlight
Sunlight is a great source of vitamin D. Vitamin D is a really important vitamin for your body and your brain. It helps your brain to release chemicals which improve your mood, like endorphins and serotonin. Try to go out in the sun when you can, but make sure you keep your skin and eyes safe. 30 minutes to two hours a day of sunlight is ideal. During the winter, some people become depressed because they aren't getting enough sunlight - this is known as Seasonal Affective Disorder (SAD).