I also use the method Pisces described (or sometimes another one, if I'm pretty sure the contact report gives me a good course and speed estimate and the enemy has radar). I feel that by plotting the approach I save fuel, time and get a better chance of finding even those maximum distance contacts. It also somewhat lessens the risk of getting attacked while approaching the target, since by plotting my approach is faster than by my guesstimation.
Well, actually maybe the biggest reason for me plotting the approach, is that for some curious reason I kind of like it
I wonder what my mathematics teacher would have said about this...