I guess the best way to play smart in gambling is set a limit on how much loss you can take and a goal on how much profit you can earn. Its the same thing with trading, your number 1 enemy in gambling is your emotion. Some gamblers don't know when enough is enough. Bringing someone with you when you play is a good idea to remind you if you reached your limit.
You are definitely right, mate. It's too smart, if you set up limits before you start gambling, This limit can protect you for losing a huge amount without any consideration, So I advise a lot of people to do that before they start, also you should set some rules and follow it, By the way, If we ask people why they start gambling, the most of them will answer that they want to be rich, I think this is not a specifc goal to achieve. So, the best think is to set a goal every a short period and try to achieve it using your own rules.