Tips learned from CBT Nuggets...

1. Use Multipoint instead of point-to-point frame-relay type when only one side of the link requires a sub-interface.
2. Use 0.0.0.0 wildcard mask to be sure what interface is in the routing processes. I always put the actual network mask, thinking that network will be advertised into OSPF, not what interface will participate in OSPF.
3. To advertise loopbacks as /24, you can use point-to-point network type under interface configuration. (ip ospf network point-to-point).
3a. You can also redistribute connected use route-map.
4. Use large metrics when redistributing another routing process into another. In most instances, you would not want a redistributed route to be preferred over a native route, although I've seen weirder requests on the IEWB practice labs.
5. Type 1 OSPF external routes will calculate their own metric across the path. Type 2 external routes will remain the same across the routing domain.
6. Use neighbor statements at the hub router only in a hub-and-spoke frame-relay network.