As the questions says, when do you stop? your point of no return?
a. at least double your money, then stop
b. you only stop when you have lost all your bankroll money and then blame the casino?
c. or you are a superstitions gambler, when you have signs like losing 3 straight in a row, then you quit because you know that you're having a bad luck
d. you stop when you are at least break even
I didn't include chasing your losses as obviously you might to continue.
Gamble is just like reggae music, you can't stop reggae but you can reduce the volume. If you're into gambling, there is no limit or those things you listed above can stop a gambler. Gambler only reduce his stake when his losing more money, he will never stop except he has no funds to continue.
The only way to stop gambling is never to get involve, once you are in, its so hard to stop than to begins. Its fun, and some days you win and sort some bills out. Some days you are depressed for losing money, you should have used for other stuff.