no easy solution to the effects im afraid...
for starters i use nothing but free software, the models are sketchup basic 100% and i use an old program called photo impact (comperable to photoshop) that was packaged with Aiptek's hyper pen (which ironically i dont use) the version i have came out in like 2002 maybe?- nothing i make cost me a dime.
in my model i use the shadow and fog functions (if you look at the styles in my model you see i also use a fog overlay that wont obscure my background the way sketchup fog does), and take into consideration the light cast by what im adding, then i export a 2d
image and open it with photo impact.
with that i use the creative lighting and particle functions and not much else. oh and also the airbrush feature to touch up the smoke effects.
the rest is just manual labor placing the effects and touching it up.
also i've found that just a simple blur at the end makes the line quality all look better.