What is the best protocol for managing individual solicitation and mailing preferences?

Answer

Mark individual solicitation and mailing preferences on the constituent record.

If a desired preference is not provided, you can create a new custom field to capture a new preference.

Ensure that the saved search driving every relevant business process, excludes or includes the record according to the preferences. 

Example

You have a constituent who has indicated that they do not want to be called.

SuiteDonor provides you a preference to mark the constituent "do not call."

In saved searches that define lists of constituents, you will include the value of the do not call field so at a glance you and see which constituents would not like to be called.

If you have saved search that defines a call list (for example, donors who gave over $5K and get a phone call from the executive director), you would exclude all donors who are marked "do not call" from that saved search. If your executive director simply looks at a generic saved search of donors who gave over $5K, you would include the communication preference fields in that saved search so the executive director can see who they should and should not call.  

Context

Most processes in NetSuite are driven by a saved search that defines the universe of record (customer records, transaction records, etc.) that are being worked with.

Preferences are coded usually a check box custom fields on the customer record.

The value of the custom field will define whether a record should be included or excluded.