I gamble only for the fun of it. Just assume I am gonna lose. Try to give myself a limit. When I lose the limit, Time to stop.
actually im gamble only for fun too, but at last addicted to it. and its not fun anymore 
i dont believe in any safe method, how safe you want? when its come to gambling, its always a risk there..
but i believe depends on luck and own greed, ask self how much u can lose and how much you wanna win?