You shouldn't be using the clutch when braking. Only pull it in just before the bike would stall. Reason being is that you lose any available engine braking (obviously you want all the help you can get when braking in an emergancy) and so the braking distance is increased a fait bit.
Sorry Adreis, but I don't agree that releasing the brake will cause it to spin. Try it for yourself.. go to a car park or on a quiet road, lock up the back brake (make sure you're going in a straight line with the bike upright!
) and then release it. I've never found that releasing the brakes after they've locked causes a loss of control.. only helps in my experience.
Of course I could be completely wrong here, but I'm just speaking from my personal experience