I'm stubbornly continuing to use my ipad for quick sketch sessions with a model. Mainly because it keeps me focused on gesture and doesn't let me start finished some small part of the drawing before getting the whole thing down–something I'm way too likely to do. Most of my time on this sketch was spent drawing the faint thin lines. Only with about 5 minutes left did I add the heavier outlines and then the not real great shading. Moving beyond line art is the hardest part do ipad drawing for me. But I think I got the weight on her left arm and that's about all I'm going for these days.
Unfortunately I read too much and what I've been getting lately is that lines are just artificial constructs and should be avoided if you want a good solid figure, and I'm nit too clear on how to draw without them.