Never set more for gambling then I think should be small allocation for gambling should not be more than 5% in my opinion.
Other needs are more important than gambling when there is some left over from your income then please use it for gambling.
It is better to gamble on weekends, do not gamble every day this can drain all your money, and you will not have time for family.
When winning, then make sure the withdrawal must be done, for example 70% withdrawn 30% played again, the important thing is that you have secured your winnings,
Never gamble because of desire, but gamble when you are ready to lose money because it is certain that gambling in the end you will lose.