In my experience, I usually just stop when I lose my bankroll. That is my rule when I gamble. No bankroll = no gambling. That is basically it. I suggest you set a fixed bankroll too. Like for example, every session you place only $10 to play. If you lose that $10, then better luck next time. If you double or triple, or reach whatever your target winnings is then you withdraw it immediately.
Right set plan and follows it ,the very reason why you set goals is to follow it will benefited you anyways. Self control and not being greedy is the key .learn to enjoy and be contented.