There's no such thing. You can't play gambling in a smart way, there are no strategies. Only luck, that's all you need to win. You never know when luck comes though, so we have to control ourselves whenever we're gambling.
Going for gambling only for entertainment must be one of smart way. But most of us are not ready for that. We all want to have profits from gambling, that is the reason gambling stays so smarter than gamblers.
if you are going play gambling only for entertainment then why are you putting money in risk, as there are so many other ways of entertainment, i think you can play gambling in a smart way if he limited his gambling to a fixed amount and never try to increase that limit which he can bare to lose in gambling.