Ask what would have to be true for you to be wrong
Considering the opposite is one of the few debiasing techniques that actually holds up.
Do this
Before committing to a judgement, write down what evidence would change your mind, and generate the strongest case against your position. Do it in writing, and do it before you have argued for your view publicly.
Why it works
Explicitly considering alternatives reduces overconfidence, hindsight bias and anchoring across a range of studies. It works because the default failure is not stupidity but one-sided search - the mind stops looking once it has a satisfying answer.
Where it fails
Most debiasing techniques transfer poorly outside the lab, and this one is no exception. It also fails on identity-relevant beliefs, where more reasoning capacity tends to produce better rationalisation rather than more accuracy.
How you’ll know
If you cannot name a piece of evidence that would move you, you are not holding a belief - you are holding a position.