The document provides 10 usability tips for designing intuitive and user-friendly interfaces. The tips include keeping the user informed of their location and available actions, avoiding frustration through back buttons and unnecessary reloads, respecting the user's time through remembering their data and progress, using consistent navigation, anticipating and clearly addressing errors, following the 80/20 rule to focus on core functionality, going with established design conventions, and extensively testing interfaces with real users. The most important tip is to test designs with users as early and often as possible.