This talk, "Debugging with the Scientific Method" changed how I debug problems. I try to watch it once every year or two.
tl;dr, when debugging people naturally form a hypothesis about what is going wrong and then set about gathering evidence to support or refute that hypothesis. When you do so unconciously you are very prone to biases of all sorts, most importantly confirmation bias.
When you do so mindfully, and Write It All Down then you are much more likely to a) come up with an evidence gathering exercise which will usefully falsify your hypothesis, and b) respect the gathered evidence, reject the now false hypothesis, and move on to a new one.