Better to start braking a little earlier then later, you loose much less with braking earlier a bit then if you miss the braking point.
Also start the braking not from the edge of the road, but more towards the middle, so you can brake in a straight line towards the outer edge of the road at the end of the braking zone, from there start the corner from as wide as possible and get the apex tight.
Also you want to get the nose of the car pointing towards the apex already during the end of the braking...