Nisargadatta MaharajJust keep in mind the feeling 'I am', merge in it, till your mind and feeling become one. By repeated attempts you will stumble on the right balance of attention and affection and your mind will be firmly established in the thought-feeling 'I am'. Whatever you think, say, or do, this sense of immutable and affectionate being remains as the ever-present background of the mind.

Nisargadatta Maharaj

Ātma Bodha
Self-Knowledge, by Śaṅkarāchārya

Reference Materials:

Video/Audio Lectures

Swami Paramarthananda
32 classes (~30 mins each) 1 | 2

Swami Anubhavananda
6 classes (~75 mins each)

Atmabodha of Shankaracharya 2 of 6 @ Coimbatore 2016 (English)20161211 070552 NR YT

Swami Shantananda
15 classes (~60 mins each)

Swami Sarveshananda
17 classes (~60 - 90 mins each)

Swami Ishwarananda
5 classes (~65 mins each)

Atma Bodha - Part 2

Swami Tattvavidananda
7 classes (search for "Atmabodha" on the linked page)