Train the ability to observe.
There are typically two types of people:
1) People that hold on to one hypothesis or theory and try to fit everything into that theory.
2) and the people that don't even create their own theory but are rather in a constant state of learning.
You need both of these modes but one that gets under appreciated is observing. The thing is most people see the world around them but little people observe it. The thing is that you can't teach observing its an individual process you do yourself - to train your method, thoughtfulness, attention, focus and awareness.
Observing requires you to look at the environment around you and notice things. To point things out. Why does this person do that? What does this person where the same clothes? Why is the shop set up this way?
Instead of confirming a theory or in a state of learning - we put ourselves in a state of observing. Pulling out from reality what is likely to be true, cutting out what is likely to be wrong and then making deductions from an unbiased, open mind.