Contrast is also a factor, all good draws need lots of contrast, white whites and black blacks...or the same thing in color. I will try to give you a few of these in color tomorrow as examples.
Nice try. It looks like a cone because the shadow is coming forward, and yet the light spot is also on the front, and that conflicts. Try putting the light directly on the top left edge
Shadows get darker at the edges of a round object. Lots darker. The cast shadow on the ground needs to be very dark right underneath the bottom of the ball and there needs to be a piece of reflected light at the bottom separating the dark shadow on the ball from the dark cast shadow on the ground. I think using a lighter opacity setting too would let you build up layers easier. I will draw one for you on this one tomorrow, very late here now. :)
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