in water, master it head up first on a rope( free imersion) in FRC doing mouthfill on the surface. Then in FRC go for an explosive mouthfill at around -3m( or take it deeper for difficulty level increase) head up pulling your self down the rope. ( after the mouthfill i swallow once to feel the epiglotis and keep it closed ) Keep your tubes open always..it is like driving an automatic car
then repeat in head down position ....
i find it easier with just a noseclip,.. you don't have to worry about equalizing the mask.
don't hammer the training you'll get a sticky ear then get fustrated.. small good doses.
have fun
