When mentoring other developers and managers, I get asked a lot what process I go through when I am picking my battles. To be honest, the one consistent thing I look to is my manifesto. Defined as "a written statement declaring publicly the intentions, motives, or views of its issuer," a manifesto is a powerful way to communicate your values and beliefs. While I have a personal manifesto for my everyday life, I have this easily accessible where I do my work.
As I get better at putting my beliefs and values into words, this will continue to evolve.
A Programmer's Manifesto
Act ethically in & out of code. Your comments are missives to both your future self and to others. Think globally, code locally. Quality begins with the API. Quality ends with the experience. Always value the work of others. Testing tests the problems we know we know. Do not miss opportunities to learn. The existential nature of all code is to solve a problem.
A Manifesto of a Manager
Leadership is not management. Talent is not infinite. Optimize for people; the work will follow. Success is the success of others. Create opportunities. Act with the highest integrity. Remember you once wrote more than emails.