Asking questions, doubting, being curious, thinking, contemplating, reflection, analysis, diagnosis. No specific technique, just using the capacities of consciousness in awareness of deficits like fallacies and cognitive biases to see things as they are.

The layer of past experiences as you call it, is more of an issue if attachment is still a large part of the psychological framework someone is in. I have talked a few times about attachment and the need to let go. There is always an influence of everything you have previously taken in as knowledge, from birth to death. But the degree of attachment that keeps you locked into it, can be alleviate and removed, so that we don't block ourselves from learning more accurate information about reality.

Thanks for the feedback as usual. ;)