ok, here is my bite.
the first one is plain not interesting.
the background id way distracting.
put a white or black background behind it and get a litte lower on the angle and with some side lighting your in business.
the second one has a yellow over cast and again, THE BACKGROUND makes the picture look like a snapshot and not like a planned picture.
now, the third one has a potential ! background is still not so god but i take you had no choice, crop all the left side of the picture untill the edge almost touch the apple (get rid of the kid scratching his head) and the picture will look nicer.
hope this helps
most important.. keep practicing and watch whats happening behind your subject