Lucid Dreaming/Reality Checks/Identity
This will be a more effective technique for some people than others. If you have noticed a pattern in your dreams of fluid or different identities, then this might work for you. Try the 'zoom' method, at intervals throughout the day take brief note of your immediate identity, location and activity, and then expand the frame a bit to check that fits coherently with your life situation. "e.g. I am writing in my living room, I work and live in Oxford and I'm 27, my name is Ethan and I live with friends."
Examples of this reality check working
I was swimming across a lake to my house. I wondered why there was a lake by my house, and the moment of confusion that I felt triggered me to perform an identity check. I was a child, a boy, and I didn't know what country I was in, possibly Switzerland. I recalled that I am an adult woman who has always lived in England, and therefore must be dreaming.
I was late for an exam. The feeling of anxiety prompted me to perform an identity check, and I realised that I could not be sitting an exam in a school since I had left school years ago, and therefore must be dreaming.
Examples of this reality check failing
I woke up and found myself in my bed in the shared house in London where I currently live, I went quickly through my name, age and gender and they all fitted with my life situation. However when I did a breathing reality check I discovered that it was a false awakening.
I was late for an exam. The feeling of anxiety prompted me to perform an identity check, but then a teacher arrived and explained that I had to take the exam again because they had lost my previous certificates. I accepted this explanation at face value and neglected to complete the identity check.