overload of light
stripping and sexually humiliating prisoners
threatening to torture and rape prisoners
threatening prisoners' families
making prisoners stand, sit etc. in uncomfortable positions to induce pain
denial of satisfaction of basic rights and needs such as food, bedding, clothing and exercise
deliberate cultural insensitivity and intolerance
use of painful "restraint" techniques
Don't be fooled - these tactics ARE TORTURE, and are defined as such both by the UN and by experts in trauma. Their role is to break down the sense of personality of the prisoner and to deliberately induce psychological trauma and crisis.
They are directly referred to in CIA handbooks - so the photos from abu Ghraib show a systematic pattern of torture, NOT rogue acts by a few stupid/evil/misguided soldiers.