To send an SMS using TypeScript and Twilio, one needs to set up a new project with TypeScript installed, install the required dependencies, including the Twilio Node module, create a `tsconfig.json` file, write a script to compile the TypeScript to JavaScript, set environment variables for the account SID, auth token, phone numbers and message body, then use these values to initialize a Twilio API client and send an SMS. This requires understanding of TypeScript type system, tooling, and how to handle errors and conditional statements in the code.