/ic/ - Artwork/Critique

I struggle with being accurate when copying images.
I spent about 3 hours trying to copy this image, but many obvious errors appeared when I overlaid my sketch on the original.
I mismeasure one thing like the length of the shoulders, and the whole drawing gets thrown off.
Is this a normal part of learning to draw? I do feel like I'm getting a bit better with each attempt, but is there more I can do to improve in addition to practicing more?