An earlier support request asked how to create a subtheme and also includes the answer:
http://drupal.org/node/492304
This documentation should go into the README.txt and somewhere on the Blueprint main web page. It would also be nice if a shell script were included in the distribution, such as the ones for Zen,
http://drupal.org/node/336368
Comments
Comment #1
metastate commentedI noticed someone has added sub-theming instructions to the Blueprint documentation page: http://drupal.org/node/396278
I would recommend using a sub-theme, rather than adding custom CSS files to the Blueprint theme, as it currently says in the README.txt and documentation. Most people will want/need to theme more than just the CSS. Keeping all customizations in a sub-theme allows for easier upgrade to newer versions of the Blueprint theme in the future.
Comment #2
designerbrent commented