Here is one of mine. Inks and colors are MyPaint, panels and lettering is Inkscape.
I started with MyPaint for sketching. Then I did the inks in MyPaint (sometimes after scaling up with GIMP or Graphics Magick because I love sketching super low rez), then I traced them with potrace and made flats in inkscape, and I did the panels and word balloons, and then I bring the whole thing back into MyPaint lettered and all, use the flats for Destination In layers in Mypaint where I finally did the colors. I like doing the panels and lettering early, like Sienkiewicz also does. It makes sense to me.