There are many guided meditations for getting in contact with your higher-self.
Lazaris' first book had a good one in the back of it.
But mostly it is just telling your higher-self, "if you are out there, please show me"
Basically any kind of permission to pass across the veil.
You have free will, and in order to preserve that, finding God or your higher-self has to be by choice, and has to be initiated from your side.