Working through Paint.NET on a drawing, I thought of a few features that I would find useful, and figured I should mention them...
"Variable" lines: Basically an alteration or enhancement to the line tool that would allow it to shrink or grow from one size to another (allowing more of a 'brush stroke' like line). Not sure about feasibility or complexity though.
A soft brush: Some times I was wishing for a brush that wasn't a solid color, but faded from intense inside to transparent on the edge. I might be missing something, but I couldn't find a soft brush in Paint.NET...
(and a half)
More Gradient Options: The gradient tool is nice, but I found myself struggling with it often enough, the circle gradient being too sharp a curve to be useful. Not sure if this could be fixed by zooming way out and making a giant (cropped) circular gradient, but a 'circle size' option might be nice.
If any of these features are already plugins or just hidden somewhere, it would be helpful if someone could point me to where I could find them.