I experienced biofeedback at Mayo Clinic's Pain Rehab Center. I learned a lot about what I'd been doing wrong.

Being hooked up to biofeedback monitors allowed me to watch and witness how tense my shoulders were and how much chest breathing was used instead of belly breathing.

Pain causes stress and stress causes tension and tension causes more pain and around and around we go. It took me 5 sessions to get to a point of being able to recognize how low my shoulders needed to be dropped in order to be fully relaxed, and just how much I needed to slowwwly breath in through my nose while inflating my belly then out through my nose letting my belly deflate. I had never calmed my body like this before and it felt unnatural at first.

I had homework to do which was to lay on my back with my cell phone on my belly then practice breathing through my belly to raise and lower the phone. It helped me get the feel down. Other relaxation tricks were to study serene landscape. Also, I found that slouching into my seat a little more allowed me to loosen my body instead of the normal erect posture I was always trying to uphold.

Like @sueinmn mentions, diaphragmatic breathing is a useful tool to calm the central nervous system and help reduce/control pain. Scheduling breathing breaks throughout the day, to build a routine and allow diaphragmatic breathing to become natural, is a great way to get started.

Breathing techniques can be used anytime and anywhere, which is the beauty of this pain management
tool.

How long have you tried using breathing techniques?