The skins I have released are, for the most part, generalized versions of skins I have created for my own site. For instance, the
CivilWar skin available for 3.0 is a generalized version of the
AFblue skin on my Wormhole Crossing site. The only changes I made to CivilWar was the removal of the header image. Adding a custom header image to an existing skin will be the simplest way for you to personalize a skin for your site. In the case of AFblue, there are 2 header graphics. One for the fancy text of the site's name and the other for the picture. For AFblue, I also added some code to variables.php to rotate the header pictures.

Civil War

AFblue
The
MarineGreen skin is another example of a skin that was customized simply with the addition of a header graphic. In this case, the graphic was attached as a background image of the banner. The generalized version is
IrishMoss.

IrishMoss

MarineGreen
One more example, the
Oz skin is the customized version of the
Cobalt.

Cobalt

Oz
If you do not have the ability to create your own header image, you can often find people to create one for you.