Fingers and wrist
Drawing from the wrist had me flicking a soft graphite across my A5 sketchbook, while holding the pencil at the top and keeping my elbow and shoulder immobile.
At first I had no idea what to do but then I started experimenting with movements and ended up with interesting patterns ranging from chaotic to organic and even mechanical-looking ones.
Arm and shoulder
At arm's length
In this exercise I've taped an A1 paper to the wall so the whole surface would be at arm's length while I stand in the same spot.
I was drawing lines top to bottom, twice and then opposite direction. I've also alternated hands. Drawing from my shoulder felt stable. Surprisingly, unlike with more organic shapes, I've felt my dominant (right) hand make more straight lines.
Using my shoulder(s)
This was the absolute most fun of all the warm-up exercises. I've taped 2 A1 papers to the wall because I wanted enough of a radius for my hands. This apparently wasn't enough because my first circle ended up "squished" on the sides, as I approached the wall and my hands got "scared".
My second (smaller) circle was a bit more geometrically correct, but it still followed the same left-right squishiness of the first one. Was it the muscle memory of the first series of movements, or does my shoulder stay more true to the centre when I'm at the highest and lowest points?
Drawing from the shoulder again felt stable in both arms, but the charcoal sometimes went skipping in my fingers of the left hand, and only when it made upwards movement.