In a turn I will start off as far to the inside as safety allows. If I am going too fast while leaned over and am in danger of running off the road / hitting something and getting injured, I will stand the bike up straight, brake maximally for as long as I can, then lean the bike back over to avoid running off the road / hitting something. Using the brakes while leaned over is questionable, you need the tire traction for staying leaned over - lock up any wheel while leaned over and it will slide out from under you faster than you are going to correct for it. Leaning over more is an option at times, but when you get to the point that you can't or won't lean over more, do the above.

If I am going straight, the bike is upright, I grab the front and rear brake equally at first while I transfer weight to the rear, then start squeezing the front brake harder and harder until I stop or run out of room. If the front wheel skids let go immediately, if the rear wheel skids you can modulate or just keep it locked up, a rear wheel skidding isn't necessarily going to make you crash. In a panic situation I might let off the rear brake a tiny bit as the front takes over, I am not sure. I haven't locked up the rear wheel in a long time, I have raised the rear wheel off the ground on occassion, so I presume I might be modulating the rear to adjust for lower traction as weight is transferred to the front wheel.

There isn't any thought involved in any of this. Through practice and years of riding two wheeled vehicles, its somewhat automatic.