After posting my attempts at 'figure drawing', I asked Tao Nguyen from ProSketch what he thought. He gave some good feedback, so I have pasted it here:
"First of all, I think you're getting confused w/ the term 'figure drawing' and 'quick sketches'. When I mean figure drawing, you're basically sitting down in an enclosed/relaxed environment and there's a nude figure in front of you. Your drawings reflect more of an indepth human anatomy study. Meaning- you're taking time to study the body structure without clothes. There is no real rush and the model doesn't move as fast as the quick sketch senario. This is where you use a charcoal pencil. It's handy for getting 'tonal details'. There are some models that do 1 to 2 minute poses and that's considered a quick sketch, but you still use a charcoal pencil for this.
As for 'Quick Sketching', at Disney we're taught to quickly capture the moment in a few amount of time and line placements. (this is where the line of action comes in handy.) What you're drawing outside in the city, malls, crowded places- that's more of a 'quick sketch' term- not figure drawing. Of course you can still figure draw w/ people having clothes on. The reason for 'quick sketching' is because the drawings are candid- people will be moving unexpectedly and don't have time to pose for you like in the figure drawing environment. This is where you use pens, felt-tip markers, pencils, etc. - not charcoal pencils. The drawings are quicker and should be expressed w/ only a few simple lines to capture the moment.
Now, as for the 'Line of Action'- there's always one. It comes mostly in the form of a "C" or "S" shape. You will see it more predominently when there are things in motion- like a horse jumping, people playing sports. You can even see a line of action when someone is sleeping, sitting, reading, etc. The only reason you're having a hard time seeing the line of action is when it's facing directly at you. You'll see it better as a profile. I usually use this as a guide for my character drawing in action. Animators use this in their drawings to exaggerate thier character pose by pushing the line of action. It's in the preston blair book."
I'll hopefully be doing some proper figure drawing soon when I find out about classes in the Manchester area, but until then I'll keep on with my quick sketches.