sing from the diaphragm, develop deep breathing, the following exercise is good, take a deep breath using the diaphragm, exhale out very slowly, take another deep breath exhale out very quickly[cleansing breath] this ia yoga technique that maharashis use to develop beautiful tone, it helps with volume. Richard Bridge is taking crap, singing teachers are useful[ not for style] but for stopping singers damaging their voices through bad technique. I know I am a singer.
think about your posture