Man, if you don't know how to gamble smart. It's very easy thing to do. When you gamble and you have enough money, you just need to budget it properly. And if you are still not addicted in gambling you can apply to gamble smartly. You can also do some smart way by simply betting small amount of bitcoins/money when you bet.
Being not greedy or avoiding to be on that attitude is already considered as a good strategy and smart way of gambling. If you are responsible and you know that it can make you worst when you become greedy, you know how to gamble smartly and you will not let your emotion to fall on that state.
you have to know the power of how much you can afford to lose and don't break it no matter what happened.
stick on it and you will not put yourself in danger and gamble with your brain not only with your emotion.
Yes staying on your limit or following your set rules will be the best way to gamble smartly. Because if you are disciplined you ca be smarter than those guys that are not using their heads when gambling.