What meditation techniques did Muhammad recommend?

Meditation is completely different to prayer. I read that he meditated a lot in the Hira cave. Maybe the word ‘meditate’ was a mistranslation?

If he did meditate, what advice did he give for correct posture, breathing exercises, visual techniques (eyes opened or closed?), helpful & unhelpful concentration methods etc.
Shadow- It can be easy to call something ‘mindless’ or ‘pointless’ if you don’t learn what it actually is. Maths is pointless if you close your mind to it.
Suga- Meditation isn’t meant for mere “relaxation”. It completely trains and re-programs your mind.