In case you don't have it on your table, take a look how does the mouse looks like.
According to fact, that most of material is transparent plastic which is reflecting environment the mouse is at. Simplify the work by putting the mouse on a white background. So it's gonna be almost all white.
Start with a new document and
Rounded Rectangle Tool should provide base shape of a mouse. Set the
Radius at
100 px. Radius should be greater then width of a mouse - so the top and bottom of a mouse is fully rounded. Color is light grey -
#E5E5E5.
Add contour to our shape. Effect
Outer Glow, set in light grey color
#DBDBDB and size
3 px. Size is actually two pixels, because
Spread is set to
47%.
To darken the contour as it goes down, add effect
Drop Shadow. Set its
Angle to
90°,
Distance 1 px and
Size to
1 px. Spread 100 % makes effect not to be blurred.
If satisfied, set the
Opacity to
10 %.
"Transparent" sides of a mouse provides
Inner Glow effect,
Size 10 px, color white. It is not transparent, it is only white border. But it's fine for us.
Source: .photoshopguidesign.com