I believed that simple hard work would make it easier, but that's a fallacy. The truth is, it doesn't matter how many hours you put into a piece... there is not a simple formula that makes you improve in order to become an expert. No, the truth is... it's no one thing. It's not a formula. *Surprise, it's an art.*
In that manner, practice doesn't make perfect. You can put all the hours you want into a piece, but if it doesn't make productive improvements, then it's not going anywhere. What do I mean by productive improvements? Fixing the base issues, I guess. Fixing the lighting so it has balance; fixing the color so it's clear; defining the texture so it feels like it is what you say it is. If you're not practicing in improving that, then you're wasting time and effort.
This is when that good ol' saying comes into play: "Work smarter, not harder."