Nice job... It looks like you are improving... However, none of the drifts in the vid are actually "braking drifts"... You used the brakes to slow down, and then used a combination of either lift off or power over to initiate the drift... A "braking drift" uses the brakes to actually initiate the drift... Meaning, the foot brake is used to brake traction while scrubbing speed, and then continue on with the throttle once you have initially lost traction and/or set your angle, depending on the situation...
I had to turn the volume down, the music was grating and distasteful to my ears, but that's a personal preference...
Keep practicing, and work on linking some of those turns and/or gaining a bit more angle...
Lookin' good though...