Wire Transfer Controls

I'm wondering what everybody's controls and/or security procedures are for initiating outgoing wires, particularly those initiated by members that do not come into a branch? What do you require from the member to authorize the wire? What thresholds do you have for additional requirements? What details are you watching that will trigger additional scrutiny prior to sending the wire? Does anybody have any resources with standards/best practices on this? I'm trying to get an idea as to whether my CU measures up to others in this area.