Mothership provides a "drush" command that allows users to quickly and simply create a sub theme.

Create the sub theme

1. Install Mothership in the sites/all/themes folder.
2. Copy the mothership/NEWTHEME folder to either sites/all/themes/NEWTHEME/ or, if for a multi-site setup, the site folder sites/[sitename]/themes/NEWTHEME.
3. Rename the NEWTHEME folder. In this example, it is called "blackpearl".
4. Change the name of the .info.example file (remove the .example part and change the name, such as to blackpearl.info) and the descriptive name found in the .info file, name = The Black Pearl
5. Optional: open the template.php file and search/replace all the theme functions i.e. replace 'NEWTHEME' with 'blackpearl'.
6. The theme is now ready for assembly. Go to the Appearance page /admin/appearance/list, enable the sub theme, and set it as the default. Note: The base Mothership theme does not have to be activated.

Change an existing theme to a sub theme

If you have an existing theme, you can make use of the Mothership cleanups by adding it as the base theme in your themename.info file (Line 7 in the image).