First, open a new image with any size you want, but I used 720* 576 pixels.Than we have to draw our shape. I started from a circle, because the shading technique of a circle is a little different than the shading technique of other shapes.OK. We opened our image than fill the layer, which we are going to name as circle with white color, or just press the D, than press Ctrl+ Backspace.Get the Elliptical Marquee Tool press Shift+ Alt (this will make our ellipse more circle). Than choose for foreground color darker and for background color lighter color. Than get the gradient tool, linear gradient, choose foreground to background and fill our circle from up to down.