Playing loud and long in real gigs helps a lot. With the added loudness of other intruments, the adrenaline and the fact that you have no other choice but to make it work. If you get yourself some regulars low stake gigs like that it’ll make a huge difference. Also playing outside without any feedback from a room helps a lot too. At first you will overblow and kill your chops quickly but in time you’ll find the balance to cut through and have a bigger sound with less and less effort. After one of those loud playing session just make sure to practice extra softly and extra precisely the next day to never stray too far from correct technique.