I find it helpful to play the big phrase choreography—the shape of a phrase, making it a physical gesture with big muscles, actual exact notes be damned. Then add in notes, making it gradually more precise. But for anyone to say that slow practice is a mistake ever is just nuts! Slow practice is how we find hand and arm shapes and angles, how we listen to the sound- esp. for a non button instrument like cello. A musician who really stretches themselves toward greatness tries all the gaits at all the speeds and all the choice emphasis and every wacky thing they can think of to find something of truth in the music. Sometimes we improvise something harder and easier. A great musician is their practice- they are as fascinating as their practice methods- and the practice should be fascinating. The thing is to find one’s own method, not to do anyone else’s method. If one reaches for artistry in music, their practice must be innovative, stylistic, nimble and responsive to everything: training for flexibility. Training for facility is more like what is mentioned here- not bad, but if you want computing, computers are better suited!