The best way to improve the effectiveness of your designs is to always be seeking quality design feedback. I say quality design feedback, specifically, because not all feedback is created equal.
Receiving quality feedback is very important for all designers, including graphic designers, web designers, product designers, and UX/UI designers, as well as other types of creative professionals. High quality feedback provides designers with an alternative point of view, which will ultimately help them improve both their current and future design projects.