Approval Workflow - Some of the Directory Self-Update

As part of the deployment, we want to enable Directory Self-Updates, but some fields, like Title and Certificates, we want to go through the Workflow Approval. However, much of everything else we offer for self-update, we want to go through without approval. For example, we'd like users to be able to update addresses and phone numbers without going through a Workflow Approval.

I haven't seen any documentation on how to break out the two parts, in that we can either have Workflow Approval, or we don't. Am I missing something? Can someone point me in the right direction with some examples how to split out the two options?

Thanks!

--Michael