Here is a recent video tutorial on creating a realistic pencil sketch effect by one of my favorite sources, davrodigital (AKA David Rowley).
He utilized several filters from the gallery to get a fine pencil sketch effect which will be good to get to know, and then offers a blending of the original colors back in, the results of which I really like!
Please give it a go, and I hope to see the sketches and colored sketches that you come up with.
Interesting tutorial which I did find well presented although a bit tricky to follow. I started with a picture I had of a model of a garden shed to see what turning it into a sketch would do. I deviated slightly from the tut towards the end as in putting color back I found alternate blend modes that I preferred - of course I can't remember what they were!
I think this is the first time ever I used the Photocopy filter, always wondered what it might be good for. Interesting.
I couldn't remember all the detailed steps, but hope I got in the most important ones.
FWIW, what I do is have the video open along with PSE, then pause the video while I do the next step or two, then go back, etc. Some steps I know what to do just by listening so I don't even have to pause it for every step. It is a bit of a hassle, but I can always rewind a bit if needed.
It's never too late to be what you might have been - George Eliot