Well, when I first started and had the nova dreamer, I looked for any sign of flashing red lights. I would sometimes try to fly, but that wasn't too convenient to do in public... I would also use the text idea... look at text once, then try to change it. I would also look for strange displays on digital clocks, which happened a few times. More recently I have found the nose pinch RC to be very reliable. I pinch my nose, if I can still breathe, I'm dreaming. That's the one I mostly use now.