This is what tends to put me off from drawing. Depending on my mood, the time of day, and any number of obscure planetary alignments, I can draw either reasonably good stuff or completely crappy things, often right next to each other and in the same session (though crappy stuff tends to breed more crappy stuff out of frustration).
Greens are "good", red is bad. Actually the green ones have technical flaws in themselves, especially the top one, but they carry some kind of "life" which makes me happy with them, and I know there was a clear feeling while making them that I could see where I was going and knew what to do. By contrast, the red face was a struggle all the way, and it's evident that I pressed down hard on the pencil in frustration to try and correct mistakes without really thinking about where I went.
It's almost entirely a mental struggle with attitude, patience and temper. That's what makes it so difficult - I know that I already possess the skills to draw at a certain level (proven by results), but it's only accessible to me when I can relax and go about it in an inspired and loose manner.
Confidence is what I lack, premature self-criticism what I have in abundance.
Semirelatedly, one thing that I've noticed is the benefit of a quick glance at reference photography before starting to draw, even if the reference isn't referred back to during the rest of the drawing. Getting an initial "seed" of reality and direction can fuel the sketch even if most of the refinement is done from imagination alone, and it's almost certainly more focused and educational to spend all your time looking carefully at your drawing rather than to go back and forth between it and some pedestaled reference that reminds you of how inaccurate your copy is.
I need to draw more and think less. It is the truth.
