★★★★★
I've found shallow breathing to pretty much make my anxiety and panic attacks nonexistent pretty much overnight. I used to take deep breaths thinking it would help, but I found them to actually make things worse. Now I take slow, shallow breaths and can finally do things like drink coffee again without any real anxiety. I haven't tried all the exercises, but more information on this theory can be found by looking up the Buteyko breathing method.