Now, I saw a picture made by an artist here, and I found that it was very keen to this technique, so courtesy of the creator of this piece I would like to show some other artists here how to use a quick and efficient process of both pixeling and in general art, that will more than likely, depending on how you apply the technique and which depictions you use, will cut about a third of the original time that you would take to create a normal peice. Now this technique is something I call the Osmosis method, because in general you are doing things in a reverse order to acheive the same results, as you will see throughout this thread how this technique is applied to the following image courtesy of CC. Corp:

Now, once you get here this is where your preference comes in, about which colors are most appeasing to you in general, but they must be contradictory to the other. So in this case, I chose my usual colors of crimson (red), and teal, which alas as you will instantly tell when you are pixeling, it much easier to work with then simply white, gray, and black, especially as in this image's case, many blotches seeing as this was hand drawn. Now once you've decided there are several ways to do this, but it helps to have PS on the side so that the line conversion takes less than a few seconds, yet the way I did it was simply by changing the exact colors, gray, black, to teal, and crimson red, and this was the result:

Now I worked on the image above for a few minutes and shaded the plating near the neck, so it may look a little different. Yet now, because there is an exact contradictory in the colors, it's much easier to see what's what, what goes where, instead of having to guess if there is a very faint gray area or if the colors don't match, etc. Yet let me explain the concept of the process before you decide to assume that this simply is a faulty process.
In general when you use these two contradictory colors, you must be aware of how to use them. So when you convert this image in the first steps of the Osmosis method, you must be aware of the color tone of the colors that you are using. Now in my example of teal and crimson (dark red), you can tell that these colors will revert back to their original gray, and black state, but how do you add detail with these new colors? It's nearly the same as when using black and white to shade, but in this case you must do a pre-cautionary method before texurizing. So once you have changed the colors you must create a duplicate copy of this image in this state and save it some where, so that you can retrieve this later in the process. Next, simply start finding the blemishes in this picture and remove them, everywhere throughout the body of the image, so in general this takes a few minutes depending if you go pixel hunting or depicted removal. Yet once you do this, revert the image back to it's black, gray, and white state by either desaturation or by changing the selective colors. Now simply using a paint bucket and just do solid color tones in the area that you want, (keep in mind the pixeling comes later on).
Now, once you've added the colors you want save this copy, and close it. Find the other and open it.
Now with this other copy (uncleaned version) open it ,and begin to add shading by using a lighter or darker shade of the colors that you used to substitute for black and gray. The way that you do this is, as I shall example in my case, to make the color that you substituted for gray to be dark if you want the color to be close to black, or have the color that you substituted for black, be lighter if you want it to be closer to gray. This way you will have acute seperation between detail, so that you can work within the outlines within the confliction of mixed colors. Or faint colors that you can't depict due to their transparency with the neighboring color. So in general by using that older image that I showed you above, and by changing the colors back into their original state you will see that the plates that I colored in teal, are now a black and white shading, of which will be key in the later steps:

So now once you finished shading there are several various ways that you can go about the following steps, but I will go about my more favorable method, which would simply be desaturating (since this works best with my colors). Now once you have the gray version, go over the entire image one more time to eliminate any shading mistakes, but keep all the blemishes, and hard line mistakes. When you are satisfied with the shading, find the previous file that you were told to save a few steps back. Copy the image, and place it over the shaded image but change make sure to change this new layer's transparency setting so that is isn't as overwriting the previous layer and all the shading detail that you've spend your time doing. Then once you do this, all of the blemishes in the body of the figure should instantly be overwritten even with the transparency. Now once you've added this new layer, the solid colors you previously used will auto-format, and there won't be a need to texturizing depending on the methods of shading you applied in the previous steps, but this is the step where you can do the last final editations such as hardline edits. So all that is left is for you to make the editations to the lines, and adding small texture editations here and there to level the image or convert it to your preference, and removing the outerlying blemishes are much easier now since you have the body the of image, by drawing/creating a border along the outside of the hardlines and converting the image format, (if you haven't had it in this stage), and then delete the outerlying areas.
Once you've done these steps you will find out that it is not only much easier to apply detail, but it saves an incredible amount of time. Though even though this is only a rough outline of the steps of the Osmosis Technique, much of it simply requires experimentation to depict the full potential of this method. Yet as you can tell words in matters such as this only go so far, and I will be intending to back these words up by using this technique to apply it to the image above or a less complicated image, dependancy on exactly what time I attend to do a physical example due to the factor that I have a project going global this Sunday.
Regardless, I inquire that you use this technique because I can guarrenttee that it will save you a great amount of time, with results with along the same or better detail than before.