Configuring and managing AIP should always start with the global approach for all users. The most important task to do before you start touching the technology is to work on a clear classification schema and the associated policies. Doing the configuration is the smallest part in a classification and information project. You should consider the default labels based on your classification schema, and start without encryption and a lot of automatic classification rules. Start with the global users that understand and work with the new technology. Keep in mind to use a step-by-step approach and work through the specific requirements in the most sensitive departments, such as human resources, legal, or finance. Don't overwhelm your users and don't teach them to lie to your concept and classification system.
Here are some additional tips for data classification...