Programming

1. Write down who your customers are.
2. Write down what problem your customers have, which can be solved with your product.
3. Write down how your product can solves the problem.
4. Figure out how you can achieve that goal (this needs to be separate to step 3 - you're essentially tackling the same thing from a different perspective... helping you see things that might not be visible from the other one).
5. Anything that does not bring your product closer to the goal(s), remove it from your product.
6. Anything that would bring you closer, but isn't achievable (not enough resources, going to take too long, etc), remove those as well.

Those are not singular items. You have multiple customers (hopefully thousands). Your customers have multiple problems your product can solve. Actually solving all of those problems will require multiple things.

If that list sounds functional, that's because good design is functional. Aesthetics matter. Why do you choose a black shirt over an orange shirt with rainbow unicorns? Take the same approach for the colours on your app icon. Why do you choose jeans that are a specific length? Take that same approach for deciding how many pixels should separate two buttons on the screen.

You said you struggle with looking at a blank page. Everyone does. If you follow the steps I outlined above, then you won't be working with a blank page.