Easiest Ever Glass Button

Finished project
Download the glassbutton preset from PSP-X.com. Extract this file to your Presets directory.
Make a selection Create a new image.

Create a new image, any size, any background color. Here I'll be using a 150x150 pixel image and a medium grey background. Layers->New Raster Layer. Effects-> Artistic Effects-> Balls and Bubbles. In the preset dropdown choose "x_glassbutton". The default color on this preset is an aqua color, we can change this to any color we like by clicking on the Surface tab. You can see that the Material box is set to a tint of cyan. To change it, click on the color swatch to bring up the color picker. I think I'll make this button pink.

 See a screen capture of this step.
Drop Shadow Adding a drop shadow.

The button is actually done, what we'll do next is add some shadows and highlights to enhance the effect. Make sure you are on the top layer, the layer with the glass button. Selections-> Select All. Selections-> Float. Selections-> Load/Save Selection-> Save Selection to Alpha Channel. You can accept the default name and hit OK. Selections-> Select None. Click on the background layer in the layer control palette. Layers-> New Raster Layer. Selections-> Load/Save Selection-> Load Selection from Alpha Channel. Hit Load. Effects-> 3D Effects-> Drop Shadow. Set the offsets to 3, Opacity to 100 and Blur to 5. Move your cursor over the working image to sample a color, choose part of the glass that is very dark but not black.		 See a screen capture of this step.
Deforming the selection Another shadow to provide depth.

Add another raster layer above the drop shadow layer. Your selection should still be active, if it's not, load it again from the alpha channel. Use the Flood Fill tool Flood Fill tool to fill this selection with the same color that you used for the drop shadow. If you don't remember the color, turn off the visibility on all layers but the drop shadow and EyeDropper tool Eye Dropper it. Selections-> Select None. Adjust-> Blur-> Gaussian Blur. Set the Radius to 10. Click on the Deformation tool Deformation tool. Drag the edges of your image window out a bit so that you can see the crosshatching. Grab the bottom node of the deformation box and pull it down slightly.

  
Adding a refraction A highlight.

Add another raster layer above the shadows and below the glass button. Set the Blend Mode on this layer to Overlay and the Opacity to about 40. Click on the Airbrush tool Airbrush tool. Use the default settings for this tool except turn down the Hardness to 0. Hold down the Control key to instantly switch to eyedropper mode. Mouse over a light section of the button and click to set that as the foreground swatch color. Release the Control key and spray a refractive highlight to the lower right of the button about half on the shadow and half on the background.