well, Its a very good question cause freaks like ourselves tend to over do it or to get addicted on doing it over and over again, whether its bulking and gaining muscles and never feel big enough or cutting down and never get satisfied.
If you wanna start a cutting process or lets just say loose wieght, you have to set your goal/s from the very begining, is it to sculpt your abs., drop your waist size a little and to what size you wanna reach or to fit in certin wieght level if you compete in any sport or.....etc etc
reasons for cutting or loosing wieght could vary from one person to another. and yet the time required to achieve the desired wieght varies depend on many factors, age, sex, health condition, fitness history, cardio. fitness....etc.
So usually you stop when you achieve your cutting goal/s.
BUT YOU CAN NOT GAIN & LOOSE WIEGHT AT THE SAME TIME /Jk
Hope this answered part of your question .
Cheers buddy