Do it on every corner, once I know the corner. If its the first time I see it, no planning is possible, unless its a short street corner where you can see thru it. Still, without planning ahead its hard to get it even close to right. If there is gravel or bad chunk of pavement, I plan a line to compensate for it. Wether turn in late, or early, or double apex or whatever. Tracks do not put easy corners for you, they put in tricky ones. You know, the off camber, decreasing radius, uphill-downhill blind stuff. Yea with a crest to really throw you off. Whats a pothole?
As for braking, I make it an effort to hit the brakes, even if I am going slow enough to make the corner. It ussually nothing more than a light tap that doesnt really change my speed, just flashes the light. Just to train my hand to do it.
Well, early morning I dont plan anything. I'm a total zombie