You can export a CSV file from BigQuery using three methods: the BigQuery console export, the bq command-line tool, or the client library in various programming languages such as Node.js, Java, and Python. The first method is straightforward, while the second option requires more effort but provides flexibility through optional flags. The third method takes the most effort to set up but allows for integration in automated workflows. Before exporting, be aware of limitations, including a 1 GB data limit per file and the inability to export nested and repeated data directly to CSV. Additionally, using tools like Census can simplify the process by providing reverse ETL capabilities that make it easy to send data from BigQuery to various destinations.