I like to go back to the roots. The original Patanjali Yoga. Yama, Niyama, Asana, Pranayama, Pratyahara, Dhyana, Dharana, Samadhi. It has been a life long practice, but has worked quite well for me.

If you know Hindi the Patanjal Yoga Pradeep is the quintessential treatise on the subject, including a systematic reconciliation of the six systems of Indian Philosophy.

I've been studying the Pratyahara phase of yoga lately. The withdrawal of the senses inward away from external sensory stimuli. It is quite powerful, and opens you up to the ability to quite literally witness the formation of thoughts from subtle nothingness.