Fortunately, making a Geoshell skin isn't really that hard, especially compared to other programs. We'll get into the components of a Geoshell theme in a minute. (And for the sake of consistency, 'skin' refers to the basic Geoshell skin, while 'theme' includes all the bells and whistles like splash screen, bar colors and such.)

What You Need

• About 30 minutes. It may seem like a lot, but once you get into the swing of things, you'll be putting together Geoshell skins in your sleep in under 10, and making complete themes in 20.

• A graphics program. This can be anything, as long as it can save files in .bmp format (Windows Bitmap, the only kind of skin graphic Geoshell R4 can read). You could even use Microsoft Paint, which comes free with Windows, though you might not be able to create the fancy kinds of skins you see at places like Deviantart.

Components of a Theme

The Skin

File	Example	Description
left.bmp		The leftmost part of a horizontal bar. You can make it as wide as you want, but in the interest of minimalism, you should probably keep it small. Also, try to lead into the middle area a bit, or your icons might look a little too close to the side.
middle.bmp		This makes up about almost all of a typical Geobar. The image will be tiled many, many times, so it's a good idea to keep it from 1 to 6 pixels wide. Try to avoid using any pattern that doesn't repeat, and if it does, use one that repeats seamlessly. Also keep in mind that when you highlight a button on a Geobar, it redraws the background from this image, and any long graphic you do will be cut down to the first 21 or so pixels behind the button. So basically, don't use a pattern. Keep it simple, like the example, and save being fancy for the sides of the bar.
right.bmp		The rightmost part of a horizontal bar. It's perfectly acceptable to simply make it a mirror image of left.bmp, and indeed some people prefer both ends of their Geobar to look the same. If you want to make one fancy and the other plain, though, it's generally recommended to draw the part on the left side, and make the right side simply an endcap. You can make both elaborate, but remember that if you get carried away it can cut down on the useful area of your Geobar.
hidden.bmp		This is what you'll see when you gripper-hide a Geobar. It's usually styled after left.bmp or right.bmp, to give the effect of a retracting button area, but you can make it a completely different graphic if you wish (or simply a small shift, like a symbol changing slightly, or a dimmed light to make it look like the Geobar is 'off'). If you do style it after the side of the Geobar, make sure to erase/change the area that leads into middle.bmp, or it might look merely incomplete instead of retracted.
top.bmp		Top.bmp is to a vertical bar what left.bmp is to a horizontal one. For a quick and easy vertical bar, just use your paint program to rotate all your horizontal graphics 90 degrees to the right (so the bar is standing on its right side). Sometimes it's desirable to give the vertical bar a few changes from the horizontal, and you could even make a different bar altogether, but for the sake of consistency it's usually best to make it look as much like its horizontal counterpart as possible (while still looking good).
vmiddle.bmp		The same rules apply here as with (a rotated) middle.bmp. Treat them the same.
bottom.bmp		The bottom of your Geobar, usually styled after right.bmp. Same rules apply here as with top.bmp.
vhidden.bmp		You should get the idea. But just in case, it's the vertical version of hidden.bmp.

The final look:

Recently, menu skinning was added to Geoshell thanks to Meester Jones. Images can be set for the menu background, currently selected item, as well as menu separators. These settings are located at:

• HKCU\Software\Geo\GeoShell\ShellUI\Menu Background Skin
• HKCU\Software\Geo\GeoShell\ShellUI\Menu Selected Skin
• HKCU\Software\Geo\GeoShell\ShellUI\Menu Separator Skin
  With just these two images:
  Your menus can go from this:
  
  To this: