Notes from a great book, "Chatter The Voice in Our Head, Why It Matters, and How to Harness It". The author is Ethan Kross.

The tools include self-talk, plus tips involving interacting with others and changing your environment.

Develop the ability to “step back” from the echo chamber of your mind so you can adopt a broader, calmer, and more objective perspective.

Tools:

• Use distanced self-talk (use your name and the second-person “you” to refer to yourself).
• Imagine advising a friend (think about the advice you’d give that person, and then apply it to yourself).
• Broaden your perspective. Think about how it fits into the broader scheme of your life and the world. Think about how other people you admire would respond to the same situation.
• Reframe your experience as a challenge.
• Reinterpret your body’s chatter response. (Examples are sudden rapid breathing, pounding heartbeat, and sweaty palms. These symptoms are there not to sabotage you but to help you respond to a challenge).
• Normalize your experience. (Use the word “you” to refer to people in general when you think and talk about negative experiences.)
• Engage in mental time travel (these feelings are temporary. Think about how you’ll feel a month, a year, or even longer from now, and it’ll seem much less upsetting).
• Change the view (visualize the event in your mind from the perspective of a fly on the wall peering down on the scene).
• Write in a journal. (Focus on your experience from the perspective of a narrator. It provides you with distance from the experience.)
• Adopt the perspective of a neutral third party. (Assume the perspective of a neutral, third-party observer. The observer should want to find the best outcome for all parties involved).
• Clutch a lucky charm or embrace a superstition. (You don’t have to believe in supernatural forces to enjoy these actions. Instead, simply understanding how they harness the power of the brain to heal is enough).
• Perform a ritual. (Examples could be silent prayer, meditation).
• Pretend to be a superhero or cartoon character you admire. (You can even refer to yourself using that character’s name). This technique helps you distance yourself from your thoughts.