6. Try the superpower reality check
Seeing if you have superpowers is an easy way to figure out whether or not you're asleep. Throughout the day, try to will yourself to fly, or shoot lasers out of your eyes, or get away with wearing your underwear over your pants without being asked to leave the office. (Maybe skip that last one.)
You shouldn't actually jump off the roof to see if you can fly—if it turns out you are awake, that situation is gonna start to suck real quickly—but simply asking yourself every now and then whether or not you can do anything beyond the realm of normal human ability will turn this mental process into a habit.
Ideally, you will reach a point where you find yourself testing these theories while asleep. When you find out that you do have superpowers, that will be the heads up you need to realize that you're actually dreaming.
Then you can superhumanly beat the crap out of all those Freudian supervillains hiding out in your subconscious, like Dr. Repressed Urges and Buried Traumatic Memories Man.