Question for solo founders developing their own project

Simple question that I'm grappling with - how do you go about the whole product development process and working out what to build next?

Obviously in a big company, you've got teams of PMs and developers and designers, and you can go through a validation process. But when you're developing an early project, how structured do you make your processes for things like product discovery and ideation?

I'm relatively new to this, so keen to hear what others do. I find it's very easy to get stuck in a cycle where you just keep fixing little bugs, iterating and developing things that you think are necessary based on a few customer conversations, and what's best for the business.

I feel I might need to take a step back sometimes, and spend more time planning and thinking more thoroughly about the product development process and what the customers want.

Has anyone else thought about this much and/or have some tips on the way they do it?