GIMP Gate

These days, besides basic photo editing, I mostly use GIMP to make scanned traditional art better for web viewing, but even though I've used GIMP for a while and know what most of the tools do, I still can't figure out how to accomplish some basic things. Like color correcting my scanned pictures so that the scan really looks good and like the colors I painted. I fiddle with the sliders and curves of the color tools but with little success. Also I still don't manage to make pieces I needed to scan in parts merge seamlessly, even though I try overlapping and such. Sometimes the lines don't match and especially with color pictures the colors in the same scanned part in the overlapping area are not the same in the two halves, even though it is the same area of the painting scanned with the same scanner. I don't understand why that is or how to fix those things.

Before my rats chewed through my tablet cable I've tried using Gimp for inking and coloring, but I had trouble to apply most digital fanart tutorials, because the brushes in Gimp are apparently quite different from what Photoshop has.

I also tried to use Inkscape once, thinking it might give me nice sleek lineart (for things like my icons, which I draw), but it was an older version and I didn't really manage to make it work, and the newer versions somehow don't compite on my older Linux version on my laptop so I have given up on that.