Effective logging practices begin by identifying the questions one aims to answer, rather than simply deciding what data to log. This proactive approach ensures that essential information is readily available during unexpected system failures, as it is not feasible to alter logging in real-time emergencies. Community knowledge can guide logging practices when specific questions are not yet determined. Key aspects of system monitoring include functional correctness, performance, reliability, and security, each with its own set of questions and data requirements. While gathering comprehensive data is crucial, excessive data collection may negatively impact system performance and user privacy. Therefore, it's important to balance thorough data logging with efficient data handling and privacy considerations, ensuring all sensitive information is properly managed.