Myself, once a week.
There's no correlation between your gambling frequency and the results you get.
I mostly bet on sports, sometime there's a week where an underdog win more than favorite, sometime there's a week with full of unpredictable results. It's random and depend on how lucky your predictions is.
Gambling once a week is a way to keep yourself in control and also cut down your losses, the more you spend time in the game the more money you lose. Sports betting is a good choice and i love betting on it during the weekends only, this has helped me to manage my risks and reduce the rate of losses. like you said sports betting can be very unpredictable, there are games that you might be 100 percent sure of that might have a different outcome, this doesn't surprise me anymore because I'm already used to the system and My expectations are always low.
You are right, if we gamble ones or twice a week we can maintain a good standard of gambling, and as you have said it will not make us become addicted to gamble either. Well, addiction can start at anytime but we need to be conscious on how we gamble in terms of the amount we wager. However, even if we are gambling ones a week and we are wagering a huge amount that we can not afford to lose, we might become addicted. So the other important thing to focus on is that, we should wager the amount we can afford to lose.