Markers and manga style rendering was covered by the ArtRage guys a long while ago but for any of you that like using promarkers or copic markers, I've been experimenting with some new presets. I use real promarkers quite a lot in my illustrating and I tend to find the ArtRage felt pen isn't quite fluid or easily blendable to get the smooth and flat blends (they're also better working dark to light which is the opposite of the real ones). I have included a preset for the felt pen for working dark to light and a fluidly watercolour one but I think the custom brush ones are the most satisfying.
I have also created colour palettes based on the real life promarker and brushmarker sets. (The ArtRage guys have already got the copic colours out there on deviant art which are a great set! ).
Marker Presets
Promarker Colour Palettes