Most recent one:
- forearm looks large (nearly as thick and as long as quadriceps. The distance from your wrist to the inside of your elbow should be the same length as your foot is)
- neck should be slightly shorter. It also currently looks to be offset to the left
- navel should not be centered on the ab lines (should be slightly below six pack)
- hip flexors should stand out more
- kneecap should be centered on his left leg, lower on his right (also should be overlapped by the vastus medialis)
- his hands are larger than his feet
- his abs should appear over his ribs just below his pecs
The colors could use more contrast as your mid shades are relatively close in value.