Robert Henri, in his book The Art Spirit, said, “To have ideas one must have imagination. To express ideas one must have science.”
One way to get the “science” is drawing the model from life. You will train your eye to see what is actually there. It is different from what the camera sees. The way the light hits the figure, the color in the shadow and the highlight is important to observe from life. And the model stands longer than those people that you sketch in your sketch book, giving you more opportunity to observe.
I love to hold my pencil as I am in the photo above. It gives me more freedom of movement. The sketch becomes more of a dance over the paper. It helps promote muscle memory. If you have sketched enough in your sketchbook, you can dive right into the sketching of the figure without intimidation. Think about angles and catching the pose of the model in a lifelike, not stiff pose. And watch for the time that the model sinks into the pose and it becomes more natural. Watch for those areas where the hair hits the shoulder or where the chin hits the neck line, anywhere one line hits another.
And what about imagination? Ideas float in and out of my head at about the same speed. So it’s important for me to capture those ideas and get them down in my sketch book. The ideas that I capture, lead me to other ideas. When I see the multiple ideas in front of me on the page, I can choose which drawing best fits what I’m trying to say. When you carry your sketchbook around with you and use it, your sketching and observational ability improves immensely. And you always have something to put those gems down from your imagination.