To begin with, open a rock texture of some sort. Go to Edit>Define Pattern. We will use this a few times for both our buttons and background. Open a new image and fill it with the pattern. Create a new layer and, with the Shapes tool set to make your shape a path, then convert the path to a selection. Fill the selection with the pattern also.

In the channels palette, create a new channel. Fill your selection with white. Make black your foreground color, and apply a 4 pixel inside stroke. Now we will run 4 gaussian blurs on the selection, first set at 7, next at 4, next at 2 and lastly at 1. Here's what your channel should look like thus far:

Go back to Layer 1. If you haven't already fill the selection with the pattern. We will now apply lighting effects to this layer. Go to Filter>Render>Lighting Effects. This will help pull our buttons off the background, as right now they appear invisible against the background.

For a bit more contrast, I ran the same lighting effect twice on the same layer. Here is where I sit thus far:

Now the point was to make these buttons look embedded, but we aren't quite there yet. Reselect you buttons (Control/Command>Click on layer 1). Expand your selection by 4 pixels. Create a new layer below layer 1 and fill the selection with the pattern. Go to your Layer Styles. On this layer I want to apply an outer bevel with the following settings, though you may do so to taste. The key here is subtlety - don't go too crazy and it will look a bit more realistic.

Ok, it still needs a bit of tweaking so the buttons look recessed. Repeat the process of selecting the layer 1 buttons again. Create a new layer, make black your foreground color and do a 2 pixel outside stroke on the new layer. Drop the opacity of this layer to 75%.

This is just one little trick for creating these effects, and I'll do more in the future. This also works for text, and as you know how I love working with fonts, here's an example using text and a different texture: