Solo founders: How do you decide what to work on each day?

I use two lenses to focus my work. First, I ask myself what the the biggest bottleneck to growth is. I'm never lacking for ideas, so I review all the related strategies, tactics, and tasks I've written down that are related to the bottleneck I identify. Second, I pick a few items that seem most promising, then see if I can tweak them to optimize for learning. What questions can I answer, what knowledge can I develop whether or not the initiatives fail. I write down the questions I hope to answer, execute against the redesigned tasks, then follow up after I have enough data and see what I can glean. Helps me preserve a sense of forward momentum regardless of the growth outcome, since I'm always learning more.