How do you breathe?

There are perennial discussions here about breathing. They typically focus on bilateral vs. one sided breathing, or hypoxic vs. getting all the air you can. I'd like to change the discussion just a smidgen. Time was when I didn't think at all about how I breathed. Air came in, air went out. I've lately been thinking about breathing more consciously using my diaphragm though, and less with my rib cage. I realize that since your arms are flailing about in one form or another, there will be lots of rib cage activity, whether you're breathing or not. Still, I had this notion that if I could breathe a bit more with my diaphragm I might just change my center of gravity ever so slightly, and perhaps help me swim a bit more level. I tried it a bit, but didn't really notice a difference, until... I tried it doing breaststroke kick without a board. (I don't like kicking br with a board, because my legs sink enough as it is.) For me, if I kick br without a board I often find it kind of hard to get my chest down when in my streamline, and my back and shoulders seem to be the first things to pop up. When I breathe more with my diaphragm, it's much easier to hold that streamline underwater. That all said, I'm not really a breaststroker, so I may well have some serious stroke flaw that this change is helping me work around. I was wondering if other people have consciously practiced more diaphragmatic breathing ("yoga breathing", if you will), and whether or not they feel it's helped their swimming. Also, if you've tried it, does it seem to be stroke-specific, or does it help you in all strokes? Or does it not help you at all? S