How do I “test it”?

I’ve read a bunch of times on LessWrong about how important is to test things. It makes sure your beliefs are paying rent and helps you verify your hypotheses. Testing ideas is obviously important to science, and it’s about as obvious that testing ideas in everyday life can serve the same purpose. I know all this, and I want to be the type of person that goes out and verifies my beliefs by experiment, but still I can’t think of a single time I’ve done it. I don’t think I even recall thinking, about some everyday type of thing, “hmm how could test that?” (apart from trivial trial-error computer related things). Anyway, I was wondering if some of the you could give me some examples of times you’ve done this. I’m thinking maybe I’ll be able to pattern-match the kind of things you guys have done and hopefully recognize in the moment when I’m looking at a testable thought.

Thanks.