I've come to realize that feedback is the most valuable resource startups have. Any feedback, in either numeric value or written word is priceless in improving and guiding you towards success. Without feedback - how would you know if you're doing the right thing? How do you improve if you don't know what you're doing wrong? Our default form of feedback is $$$. Either it's negative or it's positive. But we can go beyond that. Surveys, interviews, video captures, comments, etc.
The biggest problem is getting your project in front of people in the first place. When you start from nothing with no visibility, how do you convince people to take a look?
Once they take a look, how do you capture quality feedback from them?
Let's compile our strategies here!
Networking is pretty key - start talking to the target customers / users right away and talk about your idea (as many and as much as possible). Better yet, give them a simple wireframe / low fidelity prototype / etc so they can visualize what it is you are talking about as visualizations often connect the dots for people. It might seem daunting, but I have found that people are often more than willing to meet up to talk. Utilize that time as there will be no guarantee they continue to invest themselves in continued discussion as the "innovators" that keep an open feedback loop with you are a dime a dozen. If you hear similar feedback over and over, pay extra attention to that. Try to gauge value and willingness to pay as well as ideas might sound awesome to a customer, but that doesn't mean they are actually willing to pay for it.
I think the most important thing is to launch. Once you launch your focus will be on getting users. If you can't get any users that's feedback in itself. The lack of users basically says that you are not solving any problems for your users, or you are not communicating your value prop clearly enough. I think in 30 days of customer acquisition you should be able to get at least 1 or 2 paying customers.
You can acquire customers in many ways, indie hackers is great, and so is product hunt and many other social networks out there. Getting into the flow of acquiring users and seeing how your product retains customers is also in itself feedback.
Then of course once you have customers they will tell you what works and what doesn't work, and you can use that to 'direct' your product.