For me a game changer was reading: Mastering the Core Teachings of the Buddha https://www.mctb.org/mctb2/ https://www.mctb.org/mctb2/ I moved from Transcenden

For me a game changer was reading: Mastering the Core Teachings of the Buddha https://www.mctb.org/mctb2/ https://www.mctb.org/mctb2/ I moved from Transcendental Meditation (which I had learned previously) which doesn't quite get you into these states to concentration and insight according to this book and it got me there.