Constantly assess the road surface,and never relax, particularly anywhere where you might have to do something, like brake or turn! Watch out for wet, or icy, looking areas, or any change in road condition. Be particularly careful at night, because these areas are much harder to identify. If you see a suspicious area, try to brake and steer as much as possible before you get to it, while the surface is still good. If it is water you will hear it splash. If it is black ice things will go quiet.
If you go onto ice when you are travelling in a straight line, you will continue in a straight line. If you go onto ice when you are travelling around a bend, you will probably still go in a straight line. So to repeat - brake and steer before you get to it. If you do get onto ice drive smoothly and never do anything suddenly ! If you turn the steering, or brake, while you are on the ice, it will take effect as soon as you come off it. So the less you do the more predictable the outcome.
Approach icy junctions at walking pace (photo above), and even more cautiously if downhill. Slow down to a stop, about 3 or 4 car lenghs before the junction and creep the rest of the way. One of the most dangerous things that could happen is to touch the brake at a junction onto a major road, and skid out into the passing traffic.
Approach icy left and right turns very carefully (photo above). Again slow down to a walking pace 3 or 4 car lengths before you get to the corner, and creep the rest of the way. Make sure that there is no traffic emerging from the side road, because if you slip wide on the turn you may slide into them. Also look out for ridges of ice on the corner which may cause you to slide sideways.
Parked cars at the roadside can be a real hazard (photo above). Try to ensure that your speed is steady before nearing them, because acceleration may cause your front to hop sideways. Your steering should be done very early so that you are not pointing at the car, then trying to steer away, but pointing at the gap you are trying to drive through. Then if the steering doesn't grip immediately you've got a chance to adjust it. If you can avoid ridges, between the car tracks, as they may cause you to slip sideways.