As a welfare agency our salesforce is set up around three critical objects - Contacts (a Standard Object), Client Cases and Sessions (both Custom Objects).  Our client details are held in Contacts.  A client case is created for each service type a contact receives.  Each instance of service/session is recorded in the Session object under the appropriate Client Case.

Looking at our Client Case custom object (using Field Trip) I find that 20% of the objects custom fields have never been used.  Subject to discussions with the users I would like to clear/delete some of these unused fields.

My questions are - What are the pit-falls, if any, in doing something like that? What sort of things should I keep in mind or check before taking any action?  Is there a best practice guideline/policy which can give some guidance in cleaning up unused fields?  Or should I just leave the fields?   (We are up to 61% custom field usage for the Client Case custom object).

Any feedback would be greatly appreciated.
Graeme.