The best way I can think of (short of having someone stand over your shoulder while you look) is to strudy a lot of pictures. Particularly valuable are those pictures labeled and pointing out the differences between the queens (mated and virgin), the workers and the drones. After a bit of studying you'll ask yourself, "How come I didn't see it myself?"How can one really determine who is the queen in the hive? My friend pinpoint the queen in my new hive but if it wasn't because of him, I wouldn't know.