Do not be sad.

Sadness consumes us and takes up the time we could have used to be happy. Sure it’s a long stretch to say ‘don’t be sad’ knowing that it’s easier said than done, but the next time something saddens you, do the following:

• close your eyes. place your hand over your heart, that alone should remind you of your purpose. You were made to serve Allaah subhanahu wa ta’ala. You were made for so much, fulfill your duty by making the most of your time.
• Smile. It psychologically helps you feel a little better. Even if it’s not genuine or sincere, just smile.
• Distract yourself by doing something else. If you’re thinking about your poor grades for example, think about Salaah and how you need to pray. Or perhaps go exercise or read a book.
• Talk it out. Talk to yourself. Let it out, don’t vent to anyone, vent to yourself & complain to Allaah alone.
• Remember Allaah. Remember what awaits you if you’re patient. Jennah inshaa’Allaah. 
• Remember death. Will this situation matter when you’re dying? It wont, death is the biggest obstacle, bigger than even what you’re going through.
• Remember the death of the Prophet. He went through so much that could cause any person to become depressed and upset for life, yet he had trust in Allaah and always saw the good side of things.
• Trust in Allaah. What is making you sad right now, wont continue on making you sad forever. Look back at all the other times you were sad, do they matter now? They wont matter in the future, so let go of it.
• Hug someone.
• Find a lame joke and laugh at it. That’ll liven up your spirit.
• Make duaa and lots of it. “Verily in the Remembrance of Allaah, hearts find rest.” & duaa and reading the Qur’aan are the best forms of remembrance.
• Write a letter. If you hate writing, paint or draw something and focus on it. The more you focus, the smaller your problems appear to be.
• Jump on the bed. 
• Bake something you’ve never baked before.
• Clean//organize

Feel free to add anything else.

• Recite Qur’an. The words of the Qur’an have a profound impact on our hearts. In addition to being a reminder and guidance from Allah subhanahu wa ta’ala, recitation of the Qu’ran is known to lower one’s blood pressure, heart rate, and essentially calm one both psychologically and physiologically. If you’re unable to recite it, listen to it.
• Eat chocolate. Eating chocolate increases the level of endorphins that are released in the brain and makes us happy. Dark chocolate is also healthy for you, and contains natural antioxidants. Eat it or enjoy a nice warm mug of hot chocolate.
• Go for a walk/run. Get your body moving, and marvel at the beauty of Allah’s creation.
• Spend time with your family. It’s a blessing to have one; there are people in this dunya who unfortunately, are not as fortunate.