we all know that no safe method in gambling unless quit the games when you are get win, so before we loss to much better we only spend that you can really spend and don't put another money in your pocket and don't be sad if you loss.
Precisely, the OP want to gambling, maybe that is the reason why he asked for the sage method, and quitting is far from his thought.
Anyway, there is really a safe method to gamble. One of which is to keep check of your self control, keep check of the statistics and keep check of the time. Don't get fooled by the entertainment around. It is created to distract you. Focus and keep on your strategy or adopt depends on what is need of the situation.