For easier navigation in a big amount of created custom fields on user profiles, we created custom field groups for user. You can create one in Administration > Categories > Custom field groups.
For user CF Group, we should be able to set up: Name, Visibility for User Type. We wouldn't choose any entity when creating a CF group - because of Use Case when mostly Users want same group names for different entity. Visible Tabs should be avaliable on user Profile.
Also on CRM case/task details, we display that custom fields in tabs so this way it look much better.