I've taken note on what I do when taking pictures, especially at 1.4 with minimal depth. I won't take a breath, rather I'll stop breathing for 2/3 seconds while I take the picture. Inhaling takes too long and by doing so you can end-up moving a bit as well.
Stopping breathing sounds odd, but try it instead of breathing in as if you were going to hold your breath in for 30 seconds or whatever. I find it much easier.