I used to work for an old lady who had me fill her car with gas every week regardless if it was half full, nearly empty, or nearly full. She liked to fill-up regularly, I on the other hand would drive my car until it was almost empty, then go fill it up.
2 approaches, i liked her way better.
Back to the trumpet, i have been filling my lungs with deep breaths today and with an open throat, (when i remember to... its easy to revert to the old bad way where i'd breath in through my mouth and down low to the diaphram area which i now understand to be wrong, i should be filling my lungs and chest.) and i have to say its much better, my notes are clearer through my range, my attack is phenominal! I can play much longer and best of all i'm not tired and out of breath afterwards!! Big improvement. The full chest of air just gets topped up at the notations with more nice cool air down the back of my throat. Thats is how i know im opening my throat by feeling the column of COLD air going down my throat, before i didnt get that and was just breathing in air to my abdomin without opening my throat, therefore when i let the air out my throat remained closed.
But as this new technique is very new to me, i kept going back to the bad way unconsciously, but when i remind my self what im doing i nail it and it is much better.
Just gotta keep practising this way and it should become second nature.
But i think its better to have the tank full, and regulary fill it, the old lady i worked for never had to walk to the gas station with a cannister like i often did!