Solo founder, mostly self-taught. My biggest money leak in year one wasn't tools or ads, it was building features that made perfect sense in my head and fell apart the second a real user touched them. What changed: before I build anything now, I map the whole flow in a free flowchart maker. Every screen, every branch, what happens when the user has no data yet, what happens when they cancel, where they can get stuck. Boxes and arrows, thirty minutes. Sounds trivial, but drawing it exposes ...