An apparatus for providing a reference indication to a patient tissue includes a primary locating block having a patient-specific primary mating surface contoured for mating contact with a portion of the patient tissue in a predetermined primary mating orientation custom-configured responsive to preoperative imaging of the patient tissue. At least one mounting feature is provided to the primary locating block. At least one secondary item is configured for selective engagement with the primary locating block. The secondary item is at least one of a noncustomized secondary item and a patient-specific secondary item. The secondary item provides a reference indication to at least a portion of the patient tissue. The mounting feature of the primary locating block is configured for engagement with at least one secondary item in a predetermined secondary mounting relationship. The secondary mounting relationship is custom-configured for the patient tissue responsive to preoperative imaging of the patient tissue.