Step 48 - Gradient For Highlight.
First, add layer mask on "highlight" layer by clicking layer mask icon.

Use Gradient Tool, set it "Linear Gradient", "Black to White" with "Reverse". Be sure that layer mask is still activated, and apply gradient by dragging with holding "Shift". Dragging process shown as "red arrow" on this example below.

Step 49 - Creating Shadow.
Create new layer above "Background" layer and name it "shadow 1". Then use Elliptical Marquee Tool to make ellipse selection. After that, fill selection with black color and remove selection (deselect) with "Cmd/Ctrl + D". Give Gaussian Blur with radius 9 pixels. And set the opacity layer to 50%.

Step 50 - Creating Shadow Again.
Create new layer again above "shadow 1" layer and name it "shadow 2". Then use Rectangular Marquee Tool to make rectangular selection on the bottom of icon. After that, fill selection with black color and remove selection (deselect) with "Cmd/Ctrl + D". Give Gaussian Blur with radius 5 pixels. And set the opacity layer to 80%.

Then, let's refine the shadow. Place cursor on "shadow 1" layer on the layer pallet. And use Rectangular Marquee Tool to make a selection like following example. Then give feather with radius 3 pixels. Hit delete to clear shadow on this selection.
And both "shadow 1" and "shadow 2" layer, group them into "shadow" group.
