What's a useful mental model you've put into practice
Inversion Thinking
Instead of thinking about positive outcomes (assuming everything will turn out right), turn the process on its head by thinking what could go wrong and cause you to fail so you know what and who to avoid to maximize your chance of success or at least not being surprised so you're able to make contingency plans ahead of time to compensate
You need to also do the more conventional process of thinking so you actually have an affirmative plan but it helps to know where all the mines are buried (like Minesweeper)
We create narratives bout everything we experience. If I am upset and getting worked up, why am I telling myself a story that makes me upset? When you realize your feelings are based on the story you're telling yourself, it's easier to create a different narrative, or at least separate your feelings from reality.
Like that Buddhist teaching of there being two pains: the actual pain of an arrow striking you, and the pain that arises by your reactions to the arrow. You can't control the first pain, but you have some control over the second.