My trick? No trick.. It's Science! Male and female genders are created magnetically/energetically differently.
I learned this during my Reiki practice at the end of a session when I was making sure all the client's energy centers (chakras) were unblocked with a final scan. Her Sacral Chakra responded differently, and I realized she was expecting... And she was going to have a girl. After her session, I asked if she wanted to know the sex of her baby. She said, "Yes", and I told her she was expecting a girl. And she did have a girl!
Since then, I share this in my Reiki classes and with others learning about energy work.
If you're interested in taking a Reiki class with me, or scheduling a private Reiki session for yourself, contact me at firstname.lastname@example.org