The tutorial guides developers through creating a Flask-based application that receives and handles WhatsApp messages using the Twilio WhatsApp Business API. To begin, users need to set up a virtual environment, install necessary packages, and create a development server. They then authenticate against Twilio services by storing credentials in a `.env` file and start an ngrok tunnel to make the local server accessible on the Internet. The application creates a webhook for incoming WhatsApp messages, extracts information from the message, and responds with a custom message using TwiML. Once set up, users can test their WhatsApp messaging service by sending a message to a sandbox number.