Waving is useful when you're trying to get resourses. To get armor or a dragon egg you must send your dragon.
First of all you need a Main Army. This is made up of most of your troops: LongbowMen, Battle Dragons and Armored Transports. Usualy anything But Swift Strike Dragons and Spys. First attack your target Wild or Anthropus Camp with your Main Army.
Make sure to keep around 10 Swift Strike Dragons or Spys to the side. Check how long it will take to send 1 Spy and/or Swift Strike Dragon. Don't send any SSD or Spy untill your army will arrive before your SSD and/or Spy. Then keep sending them after that untill one of them dies. the purpose of this is to see when the anthropus (and therefore items/resources) respawn. at this point, send your main army back again to collect the new resources
After recent updates waving has become much less powerful, and is harder to achive.