Watch a comedy!
Listen to upbeat music!
Focus on the beautiful, simple and wonderful nature around you!
Go for a walk while listening to music!
Talk about it with friends or family or a crisis line!
Take a nice long bubble bath with candles and light music!
Write down all the positive, beautiful things about yourself!
Final but not the least is remember to give your sadness a Time Limit then stop it at that exact time and focus on another thing completely.
Crying isn't a bad thing and everyone should allow themselves time to cry on a constant basis so it doesn't build up to a more serious situation but only allow it to run for a limited time then that's it. Move on! Do it everyday or a couple of times a day if you need it.
Also depends on what you're sad about!
On a final note: Don't ever forget you are a beautiful, lovable and deserving person and LOVE YOURSELF COMPLETELY!
Hope this makes sense as I am sick but still hope I got a message through somehow!