The first step is to create the menu in our image editor. You can use a bitmap or vector design application for this purpose as long as you are able to export slices as PNG, GIF or JPG files.
In this example, we will show the development of our Windows Vista menu:

All item text and foreground images (like small program icons at the left of the submenu items) have nothing to do with theme creation since they will be added later (in AllWebMenus).
So, lets clean up the image:

What we need is to create all possible distinct instances for the Normal, Mouse Over and Mouse Click item states.
In our example we have applied Normal and Mouse Over states.
Moreover, as seen in the image below, in the above example we have created the the following elements:

1. Left edge (or Header) for the Main Menu Group
2. Right edge (or Footer) for the Main Menu Group
3. Background for the Main Group Item (Normal State)
4. Background for the Main Group Item (Mouse Over State)
5. Background for the Sub Group Item (Normal State)
6. Background for the Sub Group Item (Mouse Over State)
7. Separator Image for the Sub Group
Note: Arrows displayed with a green border will be used as "Has Submenu" Images (which imply the presence of a submenu in specific items).