This document provides 10 tips for designing effective mobile widgets. Tip 1 is to design for mobile users who have short attention spans, divided attention, and use their device in interruptible and dynamic environments. Tip 2 is to understand what constitutes a widget as a small, lightweight application focused on a single purpose. Tip 3 is to target widgets at specific groups of users and allow for customization. Tip 4 is to follow design guidelines and not overuse device resources. Tip 5 is to leverage all of a device's capabilities. The remaining tips focus on single functionality, simplicity, engagement, social features, and ensuring the widget is fun.