Place your stencil on your page, make sure you leave plenty of room around it to add more details later. (I am using the Mystique Stencil here).
Now grab your pencil and start filling in the stencil. As you can see in the photo I'm not being too fussy about it....you can take more time with this if you wish, but you really don't need to.
Now take your blending stump and start blending. This will smooth out the pencil marks quite quickly.
Remove the stencil and this is more or less what you'll see on your page.
Now go back into your drawing with your pencil, you are going to fill in the missing bits of the gace. The line and shading breaks that you see in the lips and eyes....fill them in. This is an important step to transform the look of the work from an obvious stencil to more of an actual drawing.
Once you are done filling in the line breaks it's time to add a little more emphasis. Here I have gone over the eye lid with my pencil to darken the line as well as add the pupil to the eye.
Time to go back into the drawing with your blending stump. Soften the lines by blending into the lips, smoothing the eyelids and brow line and here's a BIG secret (so shhhhh, don't tell anyone)...by now your blending stump is covered in graphite dust...you can use it to add subtle shading wherever you want. Here I've gone in with just the blending stump to add more shadows around the nose and eye lid.
Using your pencil go ahead and draw in the shape of the face, the hairline and neck. Draw lightly so that you can go back and easily erase and modify your lines until you are happy with what you've drawn.