I made a slideshow
explaining a way to deal with antialiasing irregular lines
(eg. 2-3-2, 4-5-4-4-5 etc) rather than 'deforming' them to fit better on the pixel grid.
(an example of 'deforming' would be turning 4-5-4-4-5 into 4-4-5-5-4 or 4-4-4-5-5 -- increasing the local regularity of the line segment pattern)
Putting it in slideshow format was an experiment, I'd appreciate any feedback you have on how well it works.
This is an animation showing the steps that are broken down in the tutorial
(duplicated so you can view it zoomed in and out at the same time in sync)
Antialiasing filled shapes is also addressed, it's really just a slight change in method.
EDIT: On a completely different subject, I finally found a perfectly medium grey GTK2 + GTK3 theme -- the "MediterraneanNight-mod2" theme packaged as part of the Oxide XFCE theme
(link includes screenshot). Pretty much ideal for graphical work IMO. Most other themes I have found claim to be medium grey but are basically light grey.
EDIT2: Another subject: Gimp 2.9 has realtime indexpainting support, including full greyscale alpha masks.
All tools work on indexed images fine.
(basically, ellipse tool and more ellipse tool. No manual painting at all, no need to manually re-indexize)
Then I touched it up a bit manually -- very little changes, am showing for comparison's sake.
Then I airbrushed it (Lighten and Darken modes):
Pretty pain-free. Gimp 2.9 also has high bit depth and linear colorspace support, which you can use to calibrate your sense of what gamma-correct, mathematically precise AA looks like:
(former is Ellipse tool, latter is Freehand select tool with all vertices snapped to pixel corners. All shapes in the latter image are polygonal, even though some appear curved, so they can be fully broken down into 1px-wide gradients.)