In gambling, we will never know when is the best time to stop. So I think the best thing to do is set limits on money you put into it in each session, and do not repeat multiple sessions in short periods of time, of course.
For me the best thing to do is to stop while you are ahead, means you dont have to get greedy if you win then stop dont keep going until you lose and if you lose dont go thinking that you can win your money back, I mean if you dont learn to control yourself it is going to become something really serious just like drugs, the man makes the money no the money that makes the man.