Focus on upsetting the balance of the car going in. A middling tap of the brakes to shift forward and a sort of abrupt turn in to push the weight off to the side, putting all of the load on that single outside rear tire. It won't have enough traction to sort everything out and as such the car will rotate.
Basically figure out roughly what speed you want to be going through the corner and stay around that speed.
As you reach your entry point, step on the brakes enough that the nose of the car dips. You don't want to try and lock the brakes (which confuses a lot of people, when they hear the term braking drift they assume that's the method by which they'll be breaking traction), you're just braking to bring your cars weight over the front wheels.
Now, as the weight shifts forward like that, you need to time your turn in so that you're steering as the weight gives the front wheels a bit more grip and loosens up the rear. If you do it right you should be able to steer into the corner without any issues.
Now, at this point your weight is shifted forward thanks to the braking and outside thanks to the steering input. Your cars balance is all out of whack, and the next thing you're going to do is push it back into that rear left corner, onto that single comfort tire. This part is pretty easy, you just nail the accelerator. This will overcome the grip of that tire, and your steering inertia will rotate the car.
From here out it's all about steering technique and throttle balance, which you'll have to work out on your own through practice. One realization I came to that made everything make more sense was that your accelerator is basically shifting your grip forward and back during the drift. If you need more force in the rear to push you along or increase your angle, get on the throttle more. If you need more steering authority to decrease your angle, track through the corner better or come out of the drift, ease off the throttle. Don't make these all on/off adjustments, being smooth is key
Hope this helps a bit.
