Step 1: The Basice
1) Go to File>New
2) Create the image at 250x250 then click Advanced Options. Under Fill With:, use Transparency
3)You will now have a screen similar to the one below (Third Image)
Step 2: The Gray Background
Step 3: The Gradient
Right click on the aluminum layer and click "Alpha to Selection". Go to the new layer you created, and go to Select>Shrink... And shrink the selection by 5-10 pixels. Now go to the gradient tool and pick FG to BG. Now set the corresponding colors (First=FG Second=BG) To the colors you like. I picked a black to a red. Do a straight gradient from top to bottom.
Step 4: The Gloss
First, select the area you would like the glossy area to cover. Now fill this area with white. Go to the layers pallet and make sure the new layer you created is selected (It should have the white "gloss" part) and tone down the opacity to your likings. It's O.K. if the gloss goes into the background, we will fix this now. Right click on the layer with the gradient that we created and click "Alpha to Selection". Now go back to the gloss layer. Make sure the color gradient is still selected, even though we are on the gloss layer. MAKING SURE YOU ARE ON THE GLOSS LAYER, go to Select>Invert and hit the delete key. This should get rid of the extra gloss.