Your images show a very good understanding in a range of techniques , great use of DOF in #1 & #4 , great focus and tracking in # 2 and pin sharp detail in # 3 . My personal favorite is #1 , detail / DOF and composition all spot on , well done .
The next step once your comfortable with the basics is to look for the unusual or a way to make your images stand out from the crowd , come to think of it that's what we're all looking for
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Mark