I work under the assumption that controlling emotions in trading (and maybe in other aspects of life else as well) is practically unachievable for all or most of us. The best one can do, often with decent results, is recognizing them, and applying some (simple) self-hacks to counter these emotions.
I like to think of this process as applying 'filters' to my own biases, which I have observed over time in my own behavior and/or actions. Example: after noticing that I frequently act according to some bias (over a certain time frame, on a certain market), I will try to counter this bias by adjusting my current decisions in the opposite directions, e.g. lower my (subjective) probabilities for an upwards scenario to come true in case that, historically, I have suffered from a bullish bias in similar situations.
Like I said, kind of crude -- but so far, somewhat effective.