BACH

Bow Speed - Arm Weight - Contact Point - Hair Angle

Bow speed creates both friction and motion. It is ideally based on the thickness of the string (c string slowest speed, e string fastest) the resonance that is desired and the rhythmic value of the note being played. Ideally all notes take on the ring of our open strings and the sound ‘spins.’ Imagine painting the space to one’s right with the motion of the bow. The distribution of the bow is the planning of this speed to create the desired shape in each phrase. Open strings are the ideal practice tool for bow speed.
Arm weight refers to the transfer of energy through our diaphragm and lungs as it passes through the back, down the arm, through the hand and into the string. Think gravity and the concepts of pulling w the down bow and pushing w the up bow.
Contact point is related to the density of tone and ring that we create. For the richest sound we aim for closer to the bridge and for the most transparent toward the fingerboard. Best case when finding balance at the instrument to aim for healthy and full sound – so equidistant between fingerboard and bridge.
Hair angle creates balanced, consistent sound. With a straight bow, tilt the stick towards you, make sure the right shoulder is back and open. 

Bow Hand
Flexible – knuckles, fingers, joints

Balanced – posture that supports shoulders and elbows and wrists transferring weight into the string

Thumbs – rounded and placed in back of second finger (touching metal on the right and hair on the finger pad)

Guiding principles : *the hands are controlled by the brain so if we see and hear what we want, our muscles will follow with time and patience 
The bow is guided by the hand but driven by the breath, the back and the arm. 
The enemy of resonance is tension - squeezing in the body creates a squeezed or pressed sound.
Sinking into the string before creating a sound is ideal.
Pull through the string, right to middle to left (on the down bow)