A concise, practical guide that presents a toolkit of techniques and mental habits for making better everyday and high-stakes choices: it explains common cognitive biases and shows how to design decision processes—using pre-commitments, checklists, stop-loss rules, decision trees and probabilistic thinking—while recommending simple routines like experiments and decision journals to reduce emotional noise and align choices with long-term goals. The emphasis is on creating reproducible, low-friction rules and environments that transform messy judgment into more reliable, learnable outcomes.