When I was a kid I had a strange temper. I would flare up in a rage quickly only to return back to normal shortly after. It would happen in the face of frustration, or when I was hungry. But the thoughts of anger would be clear, well articulated in my mind. And those angry thoughts would seem totally unbelievable in the clear light of post meal blood sugar. This can only go on so long before you start to take your own thoughts with a gain of salt. I learned early that my anger could not be trusted, which lead to an internal critical eye.
Ever since I've watched out for trends and common mistakes. I kept track of when my instincts would lead me astray and when they proved to be insights even when I had little or no support for their conclusions. I have a short list of things that I'm usually wrong about and usually right about. (all of these are subject to confirmation bias just like everything else, but there is only so much you can do)
There is an assumption in folk psychology that introspection is infallible. This isn't talked about or believed in any formal way, its just that people tend to think that when they think something about themselves they are right. While this is more or less an OK way to live out your day to day existence, it is important to remember that this is not true. You can be wrong about yourself and your feelings. If you've ever tried to quit something you know this to be true.
When I quit smoking what finally made quitting possible was when I realized that the voice in my head saying I wanted another cigarette wasn't, properly speaking, me. It was the part of me that was hooked on nicotine and needed to be refuted, ignored, and ultimately forced to shut up.
What I recommend is that you look back at your life and check for patterns of errors in judgement and keep track. If you have a list of mistakes you are likely to make that you have at hand, you are less likely to make them. A thermometer that reads 10 degrees too hot in the sun isn't useless, you just need to remember to subtract 10 when its in the sun.