This tutorial explains how to create a very simple plastic button which could be using in any clean interface, or even on print.
Fill the background layer with a dark gray color. Create a new layer. Make a rectangular selection using the Rectangular Marquee tool. The size of the selection will define the future button. Reset the tool palette colors to black and white (press 'D'). Using the Linear Gradient tool make a gradient from the top of the selection to the bottom.
Create a new layer. Using the Rectangular Marquee tool make a selection 6 pixels smaller in width and height. Select the Linear Gradient tool. Set R: 37; G: 7; B: 81; HEX: 250751; as foreground and R: 68; G: 68; B: 255; HEX: 4444FF; as background. Make a gradient from the top of the selection to the bottom.
Apply Bevel And Emboss layer effect (Layer > Effects > Bevel and Emboss) to the layer with the blue gradient. Set all values as show in the picture.
The Bevel And Emboss layer effect will give some depth or 3D effect to the button.
Apply Drop Shadow layer effect (Layer > Effects > Drop Shadow) to the layer with the blue gradient. Sett all values as show in the picture.
The Drop Shadow layer effect will create the illusion that the button is above the surface.
Create a new layer. Load selection from the layer with the blue gradient. Set black as foreground color. Select Edit > Stroke in the main menu to display the Stroke dialog window. Set Width to 1 and Location to Outside. Click OK.
Create a new layer. Select the Pencil tool. Set white as foreground color. Draw lines as show in the picture on the top and left edges of the button.
Add mask to the layer with lines. Reset the tool palette color to black and white (press 'D'). Using the Linear Gradient tool and the Rectangular Marquee tool make two gradients. One for the horizontal line and another for the vertical line.
Make a selection around the horizontal line, one pixel in height. Make a gradient from the right side of the selection to the left side. Make a selection around the vertical line, one pixel in width. Make a gradient from the bottom side of the selection to the top side.
Set Opacity of the layer with the lines to 50%. Now, add some text in the middle of the button, set its Opacity to 70% and you are done!