Chapter 1To add a new theme, create a copy of an existent theme of reference in c:\windows\resources (in this example "Vista"), and edit name of folder (for example I modify "Vista" in "Mytheme").
Last passage, rename inside themes.reg (allocated in "lame" folder of RP) the correspondent string of your existent theme of reference for example Vista in MyTheme.
Then, double-click themes.reg.
In this way you've a new theme based on a existent theme, to modify.
Chapter 2Step 1: you can modify desktop color, fonts, titlebar color on "properties" > "appearance".
http://hsc.unm.edu/wbc/images/chgdisplayprop.gifWhen you've finished, click on "save as" and overwrite theme with same name.
To see "real" result with lameskin, simply change theme and set again your theme.
Step 2: edit images in "c:\windows\resources\Mytheme" with photoshop or similar.
To see "real" result with lameskin, simply change theme and set again your theme.
Chapter 3When you've completed theme, export in regedit this entire key in a file called MyTheme.reg:
HKEY_CURRENT_USER\Control Panel\Appearance\Schemes
After, delete all themes strings except your theme strings.
To publish theme please attach folder of theme allocated in c:\windows\resource and file reg in a rar or zip archive here.
I hope to be useful.