I'll be taking several BA flights next month - outbound EWR-LHR O and inbound FAO-LGW S / LGW-JFK O on one reservation, and LGW-OPO O on a separate reservation. Although I have a decent BA Avios balance, this is my first time flying BA. Suggestions on where to credit my miles? I should probably credit something to Iberia to activate my Iberia Avios account, but what about the rest?