Learn how to build a custom breakout board for testing projects and components in this 26-minute tutorial video. Discover how to create a versatile design that supports both ESP8266 D1 Mini and ESP32 Mini, breaking out most GPIO pins and adding extra power and ground connections. Follow step-by-step instructions for soldering pin headers, socket headers, and additional components. Explore the board layout, wiring diagram, and potential limitations. Gain insights into power and ground wiring, pinout connections, and testing procedures. Conclude with a final board review and discussion of alternative options for customization. Access a comprehensive parts list and written instructions to complement the video content.