Not bad!
It looks like you could push in all of your details in a bit further in zbrush to create more contrast, for example, the individual boards don't look like separate objects on the barrel.
The clothing could do with a similar treatment, just increase the range of shades that you use a bit to up the contrast between the folds a bit more. And because this is learning, go ahead and put the eyedropper to use, just sample the values right off of the model image and lay it down in the corresponding area of your drawing.
Keep at it!