Open a new image, transparent 400 x 400
Click on your preset shapes tool 
Draw a circle with the ellipse selected (or whatever shape you want your globe to be) filled with any color (color doesn't matter cause it will be deleted). To have the circle filled with color uncheck Retain Style in the shapes tool options. Then pick a color and put it in the background color selection, with nothing in the foreground color.


Convert the circle to a Raster Layer
Then make a square around the circle with your selection tool  then click inside the circle.
The selection will then go around the circle.

Go to your Layer Palette and right click on Floating Selection, and select Defloat.  Then hit Delete on your keyboard.
You'll see the "dancing ants" and nothing else.

Now you will want to choose a color that you want the glass of your globe to be.
Add a new Raster Layer
Go to Effects, 3D Cutout and use the following settings.

The Shadow Color is whatever color you want your globe glass to be.
Go to your layer Palette, click on Layer 2.  You should see a very faint circle in that layer.  Right click and delete that layer.
You should be left with Layer 1 which is blank, and Layer 3 where your circle is.
Your image should now look like this (with your color)

Now we're going to put some reflections on your glass.  Add a new Raster Layer (make sure this layer is above the rest)
Select your airbrush tool   Set your stroke color to white and use the following settings

Airbrush two streaks on the sides of your glass (or wherever you think looks good)

Go to Effects, Blur, Gaussian Blur, I used 6.94

Go to your Layer Palette and merge visible.

You have  your basic glass now.  The rest is optional I'll show you a couple different ways to fill it and save it.