I mentioned this in another thread, but I thought I'd make a separate post on it.

In my quest to find a method of drawing smooth lines, I found a plugin for Photoshop called 'Lazy Nezumi Pro'. The great thing is, it will 'hook' into virtually any application, including Artrage. While it is not a perfect solution (editable lines would be perfect), it is probably the best method of drawing clean, steady lines in Artrage. If you combine it with a smoothed pencil or ink brush, you can achieve almost vector-like results for line work.