Simple rule of thumb.... always try and keep the front wheels pointing the direction you want to go, but you also have to learn CPR (Control, Pause, Recovery)
Control is getting the car back under control when a slide happens
Pause is waiting for the loading on the suspension to take on a set position.
Recovery is getting everything straight and settled again so the car can continue in the direction you want.
Although to be honest... if you're hit from behind the chances are you're just going to be along for the ride and little you can do will change anything.