There is no special technique to it.
The goal is to remember Her in a way that one completely forgets oneself.
For this one chooses either the heart (centre of the chest) or the head (anywhere) or both to fix one’s concentration on Her Name and Form.
It takes years and years and one has to go on patiently.
It is best not to monitor or focus on what is happening within oneself.
The Divine knows our heart and will reveal whenever She Wills and the way She Wills.
There should be no over-eagerness for any experience, just the joy of remembrance.
It takes long… one has to wait whatever time it takes.