Rembrandt shows how it's done
So many figure drawing sessions begin with the warm up, where the model moves through a series of short poses, maybe 30 seconds each. As a student, and quite a long while after, I patiently endured this segment of class, dutifully scribbling in my sketchbook until the longer poses came around, when I could finally 'draw.' Now, in my maturity, I find the whole process wonderful, and I always leave a sketchbook laying open to a blank page at night so I can wake up in the morning and start the day scribbling.
The point, for starters, is to physically loosen your arm, like a dancer or an athlete stretch
ing and warming up, and get the hand-eye thing working beautifully - and to turn off the whole naming, worrying, trying-to-do-it-right side of the mind.
What's fantastically liberating is that you don't care what the drawing looks like. Its chaotic, scribbly appearance is beside the point - you are practicing the action of drawing.
So: scribble, madly, with the whole arm and stop thinking. Try to quiet down your internal monologue to complete silence, and if you can't (it's the task of a lifetime), overwhelm it with an internal joyful scream.
No outlines, no eyelashes and earlobes - big swooping gestures that capture the inner energy, the line of action, the brave battle
against gravity, the effort of being. As fast as you can.
Not like this (this is by Ingres)