For outlines, create a thin (art) brush and use no fill and black stroke.

For shadows, use no stroke and a black fill and turn down the opacity under the appearance tab while drawing.

For doing the skin base.. use grey scale with k value at  40% – no stroke with fill – it’s own layer

For  doing medium contours ( slightly darker areas on skin but not the shadows ) use use grey scale with k value at  60% – no stroke with fill – it’s own layer

For  doing medium contours ( slightly darker areas on skin but not the shadows ) use use grey scale with k value at  75% – no stroke with fill – it’s own layer

Any new color should be on it’s own layers

Pixel perfect patterns for web background repeats so no border will appear when exporting the pattern to be used.

If finding out after testing if the pattern repeats properly on a web background that it does not work right. Look for the following:

Misc. Notes

Outline Stroke actually takes a stroke, and turns it into a filled path. For example, if you have a stroked path that’s 10mm long, and 1mm wide, you’ll get a filled path that’s 10mm x 1mm, with no stroke. It doesn’t create lines, it reduces strokes on objects to filled paths.
See: http://helpx.adobe.com/illustrator/using/painting-fills-strokes.html#convert_strokes_to_compound_paths

Expand doesn’t really ‘make the effect part of the object’. If you have a filled object with a stroke, it will turn the fill into a non-stroked simple path, and the stroke into a non-stroked compound path (see the Outline Stroke command). It reduces objects to more basic Illustrator objects.
See: http://helpx.adobe.com/illustrator/using/grouping-expanding-objects.html

The Expand Appearance command does the same, but with more complex effects. It reduced the appearance of the effect into more basic Illustrator objects. A drop shadow behind a square will become a raster object behind a simple path. A square warped with the Warp command will transform to a simple path whose outlines match those of the warped square. Expand Appearance is a destructive command that removes effects and the style of the original objects cannot be easily recreated without reapplying all the original effects.

A Compound Path is a set of paths combined into one object. It can be used with filled objects to ‘cut holes’ in objects. It can be achieved with the Pathfinder command, or using Ctrl+8/Cmd+8. See:http://helpx.adobe.com/illustrator/using/combining-objects.html

Source: http://www.reddit.com/r/illustrator/comments/2cu7zd/difference_between_objectoutline_stroke/