Step One


Create a new canvas
Size: 160×160,
Background: white
Resolution: 72 pixels/inch

Set your foreground color to #F2F2F2.

Step Two


Now create a rounded rectangle using the rounded rectangle tool, with the following settings:
Radius: 15 px
Paths (see second image below)
Exclude to overlapping areas (see image below)

Step Three


Now drag out a rounded rectangle that takes up most of the canvas, and it should look like mine to the left (if not, make sure you have the same settings as I used above).

Step Four


Then, go to the paths tab (windows–paths if its not already viewable) and double click on the path, giving it a name as shown to the left.

Step Five


Next, click on the path so that it is selected, and go layer–new fill layer–solid color and choose #F2F2F2 as your fill color,

Step Six


You will now have something like the image shown to the left

Step Seven


Now, select the new layer on the layers tab, and double click on it to bring up the layer styles box (or select the layer and go layer–layer styles).

Next, enter the settings I have above for outer glow.

Step Eight


Next, copy these settings for inner glow.

Step Nine


Now you will have something like that shown to the left, and if you like you can keep it like this, and finish the tutorial here, however, I will now show how to add a nice highlight to it.

Step Ten


Create a new layer now, and then press ctrl and click on the layer with the box on it, as shown to the left.

Next, with the selection tool selected, nudge the selection up 5 pixels by pressing the up key on your keyboard 5 times.

Step Eleven


Now hold alt, then ctrl + click on the color fill layer, and you should (hopefully) get the selection shown to the left.

Now, again with the selection tool selected, nudge the selection down 8 times, and fill it in white.

Step Twelve


Next, feather the selection by 3 pixels (select–feather) and then inverse the selection (ctrl + i) and press delete, you should have something similar to that shown to the left.

Step Thirteen


This looks alright, but I don’t think that highlight looks right, so lets make it a bit narrower.

Press ctrl + t and then, whilst holding alt move the left or right anchors a little toward the center, as shown.

Conclusion


Now it is finished! You should now have something along the lines of the image shown below. ( I blurred the highlight slightly as well - filter–blur–gaussian blue)