Depending on what car u use, that will largely affect the way / technique you turn.
Assume you are using the DC2 or RX7, basically,
a) Master the out-in-out method. ie: if turning right, before your turn, keep EXTREME left, dive into the turn and when you exit, you should also end out coming from the extreme left. When in the turn, do your best to keep your car as near into the apex of the corner as you can without crashing into it.
b) General rule is the faster your speed is while approaching a corner, the earlier or sooner you must start committing yourself into the turn.
c) If necessary, brake by tapping a bit and not jamming your whole foot down on the brake peddle.
d) Try to achieve a slow (into the corner) and fast (out of the corner) control
e) Dont go into a corner with full steering wheel lock.
f) On akina, most corners are done with a "double" turn of the steering. 1st turn is gentle followed by a more committed turn.
g) Myogi is a great way to practice as you only have 1 huge turn to worry about. You can use that to practice and master your out in out method. If you do it right, with the RX7, you should be able to turn at 198-202 kmh (provided your car is full tune).
h) Dont brake unnecessary. Sometimes letting go of the accl early is good enough.
Do note that different cars require different techniques but the fundamental principles dont change or differ that much. Unless you are on a bike.

Hope this has helped.
