Thread: How to control your breathing when meditating?

I've tried meditating lately because I've heard it's a great way to train yourself to visualize, and it's good for calming down and relieving stress. But when I tried it, I couldn't control my breathing. I would inhale through the nose, then exhale through the mouth. But for some reason, I wasn't able to control my breathing and would run out of air, taking larger breaths every exhale and then running out of breath. Any help? I'd really like to meditate, it seems amazing from what I've heard.