Here's my first go at some advanced (beyond single filter) PhotoArt using Elements2. This was inspired by tutorial 04 (this thread) and tutorial 06. My work is based on a photo from
http://philip.greenspun.com. Here's a link to the original image:
http://www.photo.net/photo/pcd1313/portrait-15
In tut04, Danny notes the the colored pencil filter gives no control over the stroke direction. I overcame this limitation by expanding the canvas, rotating the layer, filtering it, rotating it back, & then cropping to the original size. I also discovered very accidently that a desaturated, blurred "ColorDodge" layer applied to tut04 variants yields an impressive simulation of a color sketch on very rough paper. This made a great new starting point for more fiddling. I also expanded on the great idea to use layer names to document steps; here I simply added empty (transparent) layers and named them with further documentation details (masking before filters for example). Probably these variants are obvious / well known / documented, but worth sharing if not.
Comments welcome, especially ideas for further improvement. (Note the .jpg files don't do justice to the originals.)
-Mark
Details on generating the art (layers from BG to top):
BG
A=BG rotate 35deg, Noise(gauss, mono, 9.5), ColorPencil (4,8,45), rotate -35. Note that I did a rough selection of the eyes & masked at 50% before running the noise & CP filters
B=BG noise(gauss, mono, 5), ColorPencil(4,8,45). Norm mode 50% opacity
C=BG rotate 35deg, ColorPencil(4,8,45), rotate -35 deg. Soft light 33%
D=empty layer -- decided not to use
E=merge visible (A,B,C)
F=copy E, CrossHatch(9,6,1), Dissolve 50%
G=merge visible (E,F)
G1=copy G, BasRelief(13,5,topleft). Overlay 38%
H= copy BG decolor
I = copy H, inverse, GaussianBlur(4,6). ColorDodge 87%
J=merge visible (H,I). ColorBurn, 24%
K=copy BG, SmartBlur(54,55,high,edge_only). Darken 10%
L= my happy accident turning off layers H&I, turned off H first & about fell out of my chair the result was so cool!

L=merge(G,I,J,K). Applied a Curves layer with mask protecting all but the background. Adjusted curve to darken background to get tone roughly matched to the rest of the image. This produces sketch2.jpg.
M= copy sketch2, MotionBlur(37,3), MotionBlur(-37,3)
N=copy M, Median(2) [eyes 50% masked]. Added a Curves layer to darken tones < 75% black. This gives sketch3.jpg.
P=merge visible (G,G1,J,K)
added a Curves layer to reduce contrast
added a PatternFill layer (lichen). Overlay 23%
added Levels layer (Output 85, 170) grouped to patternFill.
This created sketch1.jpg