Use the Style Sheet Editor tool to develop your own application-specific style sheet. Follow the recommendations given under Style Sheet Editor of the Ajax Developer documentation to add the style sheet files to your user interface, so that they will automatically be packaged with the WAR deployment file. For more information on the WAR deployment file, see Deploying the Application.
You can find further hints on how to apply a specific styling to the different controls in the respective control description chapters, for example Working with Containers and Working with Grids.