In BA, every time you fly with someone who you like, make a note of their name (code). So when you have a choice of trips, you can check if they're on your list. The problem, particularly on Long Haul is that everyone chooses destination, hence the loneliness Gammon Flaps talked of. The bidding programs will even highlight trips that have one of your 'preferred colleagues' on.
The lack of familiarity is a real problem but over the years, can be tackled.
This of course can be applied in the reverse sense to avoid the 10% of self entitled knob jockeys.