You are not required to use these patterns, just designs you can turn to if you have no clue how you want to do your shading for a file.
Welcome to this tutorial! I am Foxstep and here I will be explaining how to do basic Gaussian blurring. First, open up your desired blank on an art program. I will be using GIMP 2.8 to explain this but any other program works too. Next, select your image and delete the filling, making it transparent.
Now we're getting to the real thing...Add a new layer below the one you used for ears and above the colored layer. If you are on GIMP, just using the pencil tool would work but I know from Pixlr, just selecting hard edge on the paint tool works. Basically, you need a thick, hard-edged painting tool however you can access one in your program. Paint over desired shading areas.
Go back to the lineart layer, fill in the background with a color you haven't used ANYWHERE in your charart before (especially not black as that gets rid of your actual blank) and color select it. Press Delete. Go through every single layer and keep pressing Delete. Then deselect all (Ctrl-Shift-A for GIMP, for others, try using the Lasso Tool and clicking in a random spot on the image). And here is your finished product!