How To Sing High Notes With Your Diaphragm. Practice rationing your voice as you exhale a note, not letting it out too fast. The discussion on a diaphragm is a great starting point to learn how to sing correctly.
The easiest way to do this is to lay down and place one of your hands on your stomach, while you are breathing from your diaphragm your stomach will expand. With breath and diaphragm support, it will sound rich and strong like your chest voice. Now you must do the same thing standing up and singing.
Use your diaphragm to breathe.
Sing higher notes effortlessly in your vocal warm up. Time the length you are able to hold the note. Then, move into practicing your high notes. Using your diaphragm to sing requires taking longer and bigger breaths, which makes maintaining proper posture one of the most important things you can do to sing with ease and power.