For every trade setup you see in the market, there is risk involved so if you think every trade as a risky trade, you will risk calculated amount and upon losing, you won't feel frustrated about it. This is how you can easily manage your losses.
I agree with you, many amateur traders look at a setup and jump on it because they see potential profit. They don't realize that any setup can fail and bring loss to their account. So when you realize this important fact, only then you can control your losses.
Sometime loss giving valuable lesson in trading, which they can making evaluation trades and look what the cause of loss, if likely loss occur because trader rush in trading hence they need to have better patience to waiting best timing to enter, if likely loss occur because use high risk taker, hence ahead they must safe trade with lowest lot size.