Personal Threshold

My classes this semester have revealed to me a bittersweet weakness - for whatever reason, I seem to be able to start work strong in the gesture/idea and blocking stages, but have an intense difficulty crossing over the threshold that makes the piece look solidly finessed and finished.  I don't know the terminology for it, but I feel I can get to the stage of where it looks like it's hitting it from afar or when I blur your eyes, but in focus, there are parts that look too ambiguous, blotchy, and need tightening.  I'd provide more examples but my desktop is admittedly a bit of a mess at the moment due to the momentum of final projects, so here is the most recent example.

Once I'm at this stage, I tend to noodle around aimlessly for literal hours until some kind of happy accident occurs and I just run off of that and this has been happening for every assignment this year.  The method is very unpractical, not just for venturing forth into sophomore year, but also because I feel like I have less energy after each assignment to cross that final threshold in order to get the best possible drawing I know I can achieve.  The noodling is the only way I know how to get there, so guess I need to know what to practice over the summer...