Climbs Fully Equipped. Finds Route Than Can Be Easily And Safely "Free Soloed" And Rehearses Climbing It With Equipment.
Rehearses dozens or hundreds of times using equipment before trying the rehearsed route with minimal equipment.
Has pegs hammered into route to make it easier to grip. He climbs fully equipped and finds the easiest route with the most beneficial finger/foot holds then he climbs it repeatedly, and embeds equipment along the route as well, to facilitate the climb before climbing without a harness.
He details all of this in his "Alone On The Wall" book. I already knew this before watching the documentary. I rated this a 10/10 and now I've changed my mind because all the people watching this who know nothing about him really think he's climbing "free solo" when he's not. You've all been conned. Read one of his books already.