> Exhaling along with mental visualization of purging the mind

This one amazes me; taking deep breaths to calm myself just makes me feel weird and sometimes even more anxious, but taking deep breaths and imagining releasing a cloud of (deep purple) smoke on the exhale noticeably relaxes me. I wonder if it's the imagination component that makes it better, i.e. giving the mind something to focus on? Or maybe the timing of the exhale changes with the visualization. Either way, a great hack imo.