How did you customize your theme? Via admin panel or via FTP?

I used the admin panel, the CSS edit and the upload image function to load images to the site then referenced them in the CSS.

If you didn't customize your theme with controls on admin panel (except CSS editor), you can backup your theme in this way:
- copy ow_themes/my_theme/ folder
- copy ow_userfiles/themes/custom_mythemexxx.css file
- copy all graphic's files for your theme in ow_userfiles/themes/ folder
then upload theme's folder to ow_theme/, graphic's files to ow_userfile/themes/ and paste content of custom_mythemexxx.css file to your CSS editor in admin panel on new site.

Ah but how do I pack them up so I can share with other? So someone else can download?