Hey Nice rendering technique! It has potential for really... realistic things.
But it looks like you should focus more on just line drawing while learning anatomy.
From the looks of your drawings it looks like you press hard on your pencil and move your hand slowly and carefully while drawing.Try to draw fast with big loose flowing lines. That way you'll get rid of the stiffness some of your drawing have.
And you'll also be able to do more studies in less time. Remember that their purpose is to teach you the construction of things, so you understand how they work and later, be able to analyze what you see or imagine when drawing. And in that regard they can even be done as a few squiggly lines, as long as they show the accurate range of motion of the elbow joint for instance, or the position of the biceps in relation to the humerus.
Also, when rendering, try to make the contour work with the inside of the form. Make your contour as light as the value it is next to, or make the value as dark as the contour it's next to. Try doing this is some areas of your drawings and see what happens. You could leave the outer contour at the places it touches parts that are lit, while unifying it with the shadow values on the other side of the figure.
Or if you want to keep your contour throughout try playing a bit more with lineweight, thickening the line around areas that are shadowed, like you did in some parts of your "dinner" character.
Keep having fun