This document provides guidance on developing startup ideas using a platform thinking approach. It advises to 1) identify an unmonetized surplus that can meet an unsatisfied scarcity, 2) aggregate information to optimally match supply and demand, and 3) redefine products or services to solve problems in new ways, like AirBnB did for accommodation. The essence is considering how to create more options, better distribute existing options, or reinvent solutions by leveraging unused resources on a shared platform.