I used to do sketch -> line art -> coloring -> rendering. But for the past few months, I just use my sketch as the line art because I stressed myself out trying to make perfect line art.
I sketch on paper, photograph it with my phone, then do the lineart and everything else in krita on my computer. I also do my lineart using the polygonal lasso tool, which apparently some people find disturbing.
I've also started adding a drop shadow to my lineart because it gives it kind of a dot crawl esque look that I like.