ORC - opposite reality check
Right, I don't know if something like this already exists/has been discussed, but I propose a check for non-dreaming. This will consist of checking for non-dreamsigns, as in stuff that cannot be experienced or is unusual in (non lucid) dreams. What's the benefit of this? it's a fast and easy check to rule out you are dreaming without performing a conspicuous reality check. However when in doubt, always RC!
1. feeling tired/sleepy -you don't feel tired sleepy in dreams, with the obvious exception of a false awakening
2. feeling hot/cold - you don't feel temperatures in dreams, even in hot/cold environments/dream scenes.
3.boring/monotonous situations- this is a tricky one- you can be in boring situations in dreams like, say, being in class or on a bus/taxi/etc but these tend to fast forward pretty quickly
4.physical pain/discomfort- while you can be injured in dreams you don't feel real pain- emotional pain- yes.
note: these statements do not apply when lucidity is gained! (or their application has yet to be tested)
these findings are based solely on my (few) experiences and expert advice would help regarding what to add or correct in this list.