What to Say When You Talk to Your Self by Dr. Shad Helmstetter is an excellent book to get you started. It focuses on identifying and eliminating negative self-talk. The book argues that statements we are told about ourselves get programmed into the bain. Every statement becomes stored in our brains and this shapes our entire world view. The statements become what we say when we talk to ourselves, and what we tell ourselves becomes reality though the following causal chain: mental programming -> shapes our beliefs -> control our attitude -> impacts our feelings -> drive our actions -> determines our results. Thus, to achieve better results you must re-program your brain. He argues that this is done by changing what you say when you talk to yourself.
He has also published Negative Self-Talk and How to Change it which is an abbreviated version of the book above. I think it serves as a great re-cap, but I wouldn’t rely on that book alone.
My one critique of the book is that the solution he prefers for changing our mentral programming is specialised recorded self-talk sessions. He has developed a subscription app that allow you to listen to such carefully crafted sessions, but he doesn’t provide much information on how to craft your own self-talk sessions.
Luckily his daugher in-law Kristen Helmstetter has written Coffee Self-Talk which contains plenty of concrete advice on how to write your own self-talk sessions. It also focuses more on establishing a habit of doing the self-talk sessioins in as lirttle as 5 minutes per day – she suggest you do it while you have your morning coffee hence the name. I found this book to be a great companinon to Shad’s books.
The books above all focus on rather narrowly on changing your self-talk by overwriting it with self-talk sessions. If you are looking for a wider set of strategies you can read Chatter: The Voice in Our Head, Why it Matters, and How to Harness It by Ethan Kross. The main advice is to distance yourself from you inner dialogiue and he provide tools for achieving this – simple things like using using non-first-person pronouns or your own name in your self-talk. The book is a bit slow, but the tools provided are excellent.
For a even wider set of tools you can check out The Self-Talk Workout: Six Science-Backed Strategies to Dissolve Self-Criticism and Transform the Voice in Your Head. The strategies cast a wide net, so you should be able to apply at least one of them to your own life.