Expected Result:
. 
And if used to create water drops, result may be something like this:

NOTE: Leaf image is property of mayhem-chaos.net
Preferences:
Image size: 300x300 or as per your needs, this tutorial will work for any sized image. For this tutorial am using 300x300 image.
[NOTE]
NOTE : You can directly start reading from Step 1, if you wish to use some other image as background of the glassy ball.
[/NOTE]
Let's go forward. Create new image of 300x300 and follow steps below.
First of all we need to create the stage / floor on which we will place our glassy ball.
When you created new image, there must be a default layer named 'Background' filled with white. Delete this layer.
Add a new layer to image and name it 'floor'.
Resize the layer 'floor' to 500x500, by goung through menus, Layer > Scale layer, st width and height both to 500 and click ok.
Now go to patterns window, choose desired pattern that looks best for floor tiles, I chosen pattern named 'Parque #2 (6 x 64)', you may choose any. Drag that desired pattern and drop over the image window, which will fill the selected with pattern. Now what we have to do is change the perspective of the layer so that it looks somehow like real tiled floor.
Select 'Change perspective' tool
, click within the image window, you will see a new window appeard entitled 'Perspective', simply move this window away from the image window, since we have to change the perspective of the layer manually using mouse clicks.Now grab the top-right anchor of the layer and drag in down as shwon in following figure, then release the mosue key near the actual top-right corner of the image, see image below:

And do the same with the top-left anchor, drag and drop it over the actual top-left corner of the image, as shown here:

Now get the Perspective window back to focus and click button 'ok', which will let your modified window look as following:

Ok, upto now we just have created the floor, now we get started with the creation of glass ball.
Step 1:
Duplicate the layer named 'floor' and rename duplicated one to 'grown-texture', rightclick and press 'i' from keybard or rightclick and select menu item 'Layer to Image Size', select elliptic selection tool
and draw an elliptic selection of about 100x100 which will be the size of the ball, your image window must look something like this upto here:
Press Ctrl+i to invert selection, or go through menus, Select > Invert, then press Ctrl+K or go through menus Edit > Clear. Then again invert selection by pressing Ctrl+i.
Now go through menus, Filters > Distorts > IWrap. A new filter window will appear, where you select Deform mode to Grow and set Deform radius to 75, as shown here:

Within this new filter window, you see the image in top-left corner, simply click within it using mouse, from position A ot position B, positions are not mentioned anywhere in the window, see image below to have clear idea.

Now click button 'ok', and texture in your selection must look something like this now:

Is our ball done :l:? ofcourse not :@. we have to give it some shadows and lights so that it looks mroe real.
Step 2:
A. Create new layer over the top, and name it 'top-shadow'. Select color black from colors.
Select a blurry kind of brush something like this one:

Now select brush tool, and draw some on top of the selection, as shown here:

Set opacity of the layer to '50' %.
B. Create new layer over the top, and name it 'reflection'. Now take a solid big brush, select white color, and draw a white big dot on layer 'reflection' near the midle and top-right corner of the selection, as shown here:

Select the Erase tool, and erase corners of this dot in a way that it finally looks something like this:

We create the drop shadow now. Create new layer right over the bottom layer and name it 'shadow', so that the layers order looks like this:

Remove prior selecion by going through menus, Select > None. Again select elliptic selection tool
and draw selection on the layer 'shadow' as below, then fill it with pure black color.
Remove selection again, and go through menus, Filters > Blur > Gussian Blur, when window appears enter values
Horizontal : 20
Vertical : 20
and click button 'ok'. Then set opacity of this layer 'shadow' to '60' %.
And it is done....Your result must resemble to following one:

Related article by ClayOgre:
http://www.gimptalk....?t=6468&start=1
Let me know if you need any help, or if any step is not clearly written and you cant understand it.
regards

Help




, click in image window and change color.














