Also..how do people shade so brilliantly? Other than trial and error..they must have read tuts..?
I simply use Q-Tips to blend, no matter the shade or amount of area being blended, and I use a kneaded eraser to highlight.
What I've learned is that you have to be able to detect slight changes in the shade of what your drawing.
When you capture these tiny, minuscule details, the essence of the person's personality shines through, and it's really a neat thing to work tediously at getting every detail right, and then stepping back and going, "Wow, that looks JUST like -insert name here- !"
Another thing, there are no harsh, straight lines on a person's face in real life; every crease, fold, and shape of the skin is actually a combination of shade and light - never, EVER a line. What I'm saying, for example, is that instead of drawing a "2-D" straight line for the eyelid, draw a "3-D" flap of skin that actually has thickness to it.
Also, when I draw portraits, I always edit the picture to make it black and white; my brain processes the slight changes of light and dark a lot easier that way, instead of it having to transition from color to black-and-white.
I hope this helped!
Good luck to you.

P.S. - I only use 5 items when I draw a portrait: a kneaded eraser, white plastic eraser, a regular #2 pencil, Q-Tips, and of course, paper.
"I’m not an abstractionist. I’m not interested in the relationship of color or form or anything else. I’m interested only in expressing basic human emotions: tragedy, ecstasy, doom, and so on." - Renoir