Do you have a process in place to track the precise ROI from your promotional campaigns, or do you primarily rely on gut feelings based on campaign engagement?

Do you have a recurring or Realtime process in place to eliminate the duplicate, Inactive or Obsolete records from marketing cloud.
Note: A converted Lead, which is now a contact could be an example of the Obsolete records. Every Lead or Contact in your marketing Cloud counts as a billable contact. So having contacts that you are not engaging with your content can be costly.

Is the profile, preference and consent data updated via Marketing Cloud Preference and Subscription Centers being synced to Salesforce CRM to maintain data transparency?

Is this flow of consent information Bi-directional? I.e., if a Sales or support representative updates a contact Email consent on Sales cloud, does that reflect and get respected in the Marketing Cloud?

Are you respecting your customers preferred channel of communication - (Email or SMS) and their communication email (Personal or Work)

Are your users equipped with the appropriate and non-excessive permissions, ensuring that each individual can access only the necessary resources, and maintain data security? For instance, content managers should typically have access restricted to content-related areas.

Is your organization proficient in storing data accurately within Marketing Cloud, adhering to the appropriate data types and lengths for data types? For instance, emails should be stored as email addresses data type, and phone numbers as phone number data type and if the source of your Data is Salesforce CRM, and Contact/Lead IDs becomes the Subscriber Keys, Subscriber Key field length should be 18.

Note: incorrect data types and lengths could potentially impede query performance and accuracy