It is important to note that you should never do a reality check mindlessly. Take a minute to look around you and ask yourself if your surroundings are really logical. Ask yourself how you got there, why you are there, and where you are going.
It is of course possible to do reality checks that are unrelated to dream signs. Reality checking alone can help you induce lucid dreams.
Even if you’ve completely convinced yourself that whatever you’ve seen that is out of the ordinary is quite possible, perform one more unrelated test. Read some text, or glance at a digital clock or watch. Wait a few seconds and then do it again. If the text or time inexplicably changes, then you are in fact dreaming. Even if the time or text doesn’t change, try to focus on changing it for a moment. In dreams text often changes upon a second glance and we almost always accept it, even though clearly it is an alarming clue that we are dreaming.