Take deep breaths. Usually, when crying you're breaths shudder. Close your eyes, and think positive. If you can't stop it, just put your head down, or turn away from other people. If you're in the middle of a conversation, excuse yourself then go to the bathroom. Washing your face will help you cool down. Sometimes, you really can't stop it. Sometimes, you cry w/o knowing that you're crying.
Its better to let it out. For years I holded my tears in. no matter what I was going threw. I never let anyone see me cry. I always kept it in. now that I wanna cry I cant. When I see movies like passion of christ. Tears come down my eyes. But I still dnt cry fully. It took me a long time to understand this. But slowly as I began to share my feelings with others. My heart is beginning to open up. Slowly im breaking that guard thats on my heart. I thank God for my friends and brothers. I know I can tell them anything. But the question is why are you crying. If you ever feel like you need someone to talk to. And you get tired of carrying burdens on your shoulder. I dnt mine listening.