There are many different ways of getting into communication with someone’s higher self. At some point in your ceremonial magic journey, you’ll have to learn how to evoke purely off a name or pure energy.
Because I started with angels, who do not have sigils, I got thrown into the deep end and had to learn how to swim. Luckily, there’s a lot of occult strength in my chart, I was born on a full moon, and I almost didn’t survive my birth (another omen of occult strength), and so I was easily able to accomplish it without much hassle.
So, if I wanted to evoke someone’s higher self, I would just chant, “[Name]'s Higher Self” while altering my consciousness until I felt it’s presence or heard the spirit.
However, now, I don’t work with spirits like a ceremonial magician, I work with them like a shaman, so I would just travel to the upper world with the intent of meeting her higher-self.
PS, if you want to know the occult strength of your chart, just PM me and I can tell you what I need.