Pitches, not blueprints
As a product builder, your sketches aren’t just blueprints. They’re pitches.
If you have the opportunity to present your pitches to an inner-circle of customers, you’ll learn how to improve your work before you even start producing it.
Most designers will wait until production is done, because they’d prefer to be producing than pitching. But your pitch-first approach will improve the reception of your work, as well as giving you a ‘taste’ for the type of feedback and preferences your target audience has.