As I sat at home after a tooth extraction (unrelated to biking) I came up with two fundamental acronyms about MTB riding:
Balance your weight on the pedals going down (this allows to keep the handlebar light among other things. Very good tip for steep descending terrain
Light hands heavy feet. This is the main riding tip, the holy grail (helps with weight distribution, floating over obstacles, not loading too much the front end, etc)
Three D riding- this is about putting more or less weight on the bike using the feet: (at any moment being either light or heavy, like a wave). Light- offloading on difficult terrain floating over obstacles (two ways of doing it: lifting the weight up on elbows and pedals or quickly dropping down with elbows and feet). Heavy- pushing on the pedals down on easy safe terrain. Remember keeping light hands no matter what. This tip is from Brian Lopez's book.
Dynamic pedal as per Fluid ride video (pushing on outside pedal while cornering). Inside knee out.
The second acronym is linked to "Day" and deals with cornering.
Look at the exit of a turn
Lean the bike into the turn without leaning your body
Rotate hips (turn with your belly button)
Here you go: BLT Day LLR!