Rear brakes: I started fishtailing when I had to suddenly brake extremely hard near the bottom of a hill. I was braking front and rear, and the rear locked up. This makes the rear wheel slide to the side, since the front is still slowing down. I recovered by letting off the rear brake. I try to practice hard braking at speed occasionally, using only the front brake.

I agree with the posters about repeating a known route, with no blind corners. If you can just concentrate on riding, and already know what speed you can do on the route, it's good practice.

On wet roads, I slow way down, I don't have any way to find out how much real traction there is.