The following summarises the spiritual method advised by Sri Gaudapada, the great-guru of the more famous Sri Shankara. It is taken from Chapter 3 of Gaudapada’s Karika (Gaudapada’s commentary on the Mandukya Upanishad), one of the earliest, most authoritative and most-influential of Advaita Vedanta Scriptures.
42. The mind distracted by desires and enjoyments should be brought under control by proper means; so also the mind enjoying pleasure in inactivity (laya). For the state of inactivity is as harmful as the state of desires.
43. Turn back the mind from the enjoyment of desires, remembering that they beget only misery. Do not see the created objects, remembering that all this is the unborn Atman.
44. If the mind becomes inactive, arouse it from laya [inactivity]; if distracted, make it tranquil. Understand the nature of the mind when it contains the seed of attachment. When the mind has attained sameness, do not disturb it again.
45. The yogi must not taste the happiness arising from samadhi; he should detach himself from it by the exercise of discrimination. If his mind, after attaining steadiness, again seeks external objects, he should make it one with Atman through great effort.
46. When the mind does not lapse into inactivity [laya] and is not distracted by desires, that is to say, when it remains unshakable and does not give rise to appearances, it verily becomes Brahman.
I have written a short commentary on the above verses entitled Advaita Vedanta: Gaudapada’s Method which further explains the above verses.
You can read the entire text of Gaudapada’s Karika here: Mandukya Upanishad with Gaudapada’s Karika