I could try to give advice, but i fear its totally wrong.
1) Compared to directly go to "entire human", try to draw part per part. Focus on drawing well a anime face. Then a hand, leg, etc
Btw reminds me of a EN artist guy, that received commision. Then he said-jokingly "its only enough for one part" and he draw the eye ONLY (perfect quality) and "i gave a freeby of the eyebrows"