Before using Lovable, define what you're building. Skipping this is like starting a painting without deciding what you're painting. Answer four questions: What is this product or feature? Who is it for? Why will they use it? What is the one key action the user should take?
You're not writing a spec doc, you're setting direction. Vague ideas produce vague outputs. Use Plan mode for this stage — you can talk through ideas and let the AI ask smart questions without touching code.
Plan mode
I want to build [your idea]. Ask me any questions you need to fully understand what I want from this feature and how I envision it.