Here are useful tools:
http://dps1.travelocity.com/lognlogi...ce=TRAVELOCITY
[Travelocity Fare Listing]or the CO website will now allow you to search for qualifying fares.
http://dps1.travelocity.com/dreamMap...p_arp_name=lax may suggest cities which are worth checking out with Fare Listing.

Generally, fares to Canada (such as YYZ) will qualify. Often there are decent B or V fares to some cities with generally low fares or which are other airlines' hubs. Las year CMH and BWI were attractive from some cities. Do not wait too late in the period; last year the decent qualifying fares dried up near the end.