B777 Relief Pilot reports that auto throttle switches are not turned off after landing and are often missed during preflight resulting in taxi out with auto throttles armed. This is due to recent SOP/flow changes with no formal training.

Narrative

During taxi out on numerous B777 flights; I've observed both auto throttle switches in the ON position. They should be OFF. With the switches ON; there is a risk that a TOGA button could be pressed by accident; which would result in both throttles quickly advancing toward takeoff thrust during taxi out. This is; in my opinion; a dangerous situation. The reason this is happening is due to the recent SOP/flow changes with no formal training. The new procedures do NOT call for the auto throttle switches to be turned OFF after clearing the runway after landing; nor do they call for the inbound crew to turn them OFF after parking/shutdown. The auto throttle switches are supposed to be turned OFF by the outbound Captain during the cockpit setup checks; per the new checklist. The Captains are missing this step on most flights (6 out of 8 I've seen so far). The current SOP thus is a set-up for failure. Lets get the auto throttle switches turned OFF after parking; and then re-check them OFF during the cockpit setup flow. Leaving the auto throttles ON during any phase of operation other than takeoff; in-flight or landing is a hazard to the operation.