learn the basics--- work on trying to draw subjects as if they were walking towards you and you only had 15 seconds to capture the "essence" of the person. google gesture drawing. i teach drawing and I always tell students to worrk about refining the outline (contour) as the last step before moving on to value. i teach a sequence---1. armature and structure (armature = supports the rest of the form--- a stick figure is a simplified version of a complex armature---the skeletal system. structure---think of it as the framework that holds up the structure---like a building in construction----by drawing vertical and horizontal lines it creates references where to put everything else in the drawing--helps with anatomy, perspective, scale, etc). 2 gestural massing.---similar to cursive writing---overlapping, continuous lines that mass out the form (on top of the armature) isn't outline specific---can easily be modified, erased, and builds the volume of the form and allows you to layer overlapping lines to create value and contrast shifts. good for adding value and contrast to later. is meant to be quick, along with gesture and armature----leaves more time for refining later. 3. revisions to structure, form, etc. just like an english paper. start with the rough draft and then refine. 4. after form is accurate (and accurate with rest of composition) Edge Refinement. outlines are dangerous to start off with--like a bad relationship--they are hard to get out of---and when you try to fix one element, you realize have to fix everything. sometimes starting over is a good thing. do it better and quicker when you know what the mistakes are. 5. cross-contour (volumetric expression----like the wire frame models used for video games and cgi---controlled lines that round things out, or create directional changes---helps to separate surfaces.
don't be afraid to can your roughs---- level for white and black values and then print at different sizes---work small so you spend less time in revision---then re-scan and reprint to start adding value, contrast, contours, details etc.
tracing paper can be your best friend if you don't have time to scan for revisions. add registration marks on original (used for getting everything re-aligned after the fact---i use t's at top left-top right and bottom left---tape tracing paper down over original--trace registration marks---then make corrections, add value, all that stuff. do a little or a lot. if you scan the registration marks, will speed up overlays in any graphics program. marker does not go through tracing paper so you can add value, color, etc.
keep taking notes on your drawings---notes are more important than signatures
feng zhu is someone you should check out for traditional media as well as digital---bigtime concept artist for games, movies etc---tons of video tutorials. i've learned a lot from watching what production artists do to save time. they don't get paid by the hour usually so time is money.
http://www.youtube.com/watch?v=C3lApsNmdwM
keep at it, and make sure you learn basic perspective, anatomy and composition
good luck