The risk matrix: consider the likelihood and the impact
I do not extensively use (arguably) the most popular risk model at work, but I just realised that I've actually been using it all the time in my daily life. Recently I was involved in a discussion whether I need to take a vaccine to prevent certain disease. Turned out, I used this matrix unconsciously to evaluate whether I really need to take the vaccine.
It's remarkable to see how this mental model is adopted unconsciously to make daily decisions, not only at work settings, but in a way more casual situation.