To create a dynamic Google Sheet that updates automatically from multiple sources, I would start by identifying the data sources and ensuring they are accessible. I would use Google Sheets' built-in features like ImportRange to pull data from other Google Sheets. For data from external sources, I would consider using Google Apps Script to automate data fetching. This script can be scheduled to run at regular intervals, ensuring the sheet is always up-to-date. Additionally, I would use functions like VLOOKUP and pivot tables to organize and analyze the data effectively. Ensuring data accuracy and integrity would be a priority, so I would implement data validation checks. This approach allows for seamless integration and real-time updates, facilitating efficient data management and decision-making.