Well, Ashaman73 did say to just use the rasterized image as a template. It will at least show you what cells to pixel. After that, it's a matter of tweaking it to make it smooth. Avoid tight curves and (as the linked article says) stay away from right angles. Mainly, you just have to practice it.

Here is an example of what Ashaman73 may have been talking about. On the left is a (scaled up) curve rasterized. In the middle is an inking of the pixel curve following the template. On the right is a cleaned-up version of the curve. I'm not really a pixel artist, and a real one could probably clean it up better, but it's still pretty good for a guy who hasn't done any pixel editing in more than a decade.

Well, Ashaman73 did say to just use the rasterized image as a template. It will at least show you what cells to pixel. After that, it's a matter of tweaking it to make it smooth. Avoid tight curves and (as the linked article says) stay away from right angles. Mainly, you just have to practice it.

Here is an example of what Ashaman73 may have been talking about. On the left is a (scaled up) curve rasterized. In the middle is an inking of the pixel curve following the template. On the right is a cleaned-up version of the curve.