The higher self is the thetan or soul that you are an incarnation of, and guides you to what you are meant to accomplish in the current lifetime. They are good to call upon especially during times of pushback during manifestation or emergencies

Simply put your hands on your head and say “Higher self/ Thetan, I require ____ for the current lifetime/ for the survival of this physical body/ to fulfill my purpose. I also ask that I am open to receive help and blessings from any spirits and gods, so please open me up to receive from any deities.”

The higher self is a part of you so invoking is not required and it cannot abandon you because at that point you would not be in the physical body. You may not feel anything happening when doing this, but your higher self is always present and has heard you, so this is a very easy and effective exercise.