Looking for best practices in developing a pilot group within our Salesforce Production instance.

We are doing more integration and testing and want to roll out to Pilots vs Profiles. With the latest project, we've tested functionality and are ready to release the "Send Pardot Email" to a limited group who share the same License, Profiles, and Record Access as users who we don't want in the pilot

I've explored creating a custom Profile and can assign to select users or use the Data Loader to update a group of users, but is this the best way? 

I appreciate any insights on how others test within their production sites! 

Donna