Don't Copy Mistakes. Copy the good stuff

I notice that people are having trouble deciding what is a mistake in the rough, and what is worth preserving.Extra floating lines are mistakes. When I sketch out a rough, there are sometimes extra lines that I just put down to get the drawing started, but then as I add more form, I realise I need to make the character bigger or wider, so then draw another line around the border of the character. That's the one that's right.

Any lines that are floating around in the middle of the character that don't describe anything are mistakes. Don't copy those.
Your goal:

To preserve the life and design of the rough.

To fix the mistakes. (to see what is obviously a mistake, and what is on purpose)

To make the drawing solid, but to preserve interesting angles and subtleties of design.

Your NOT goal:

To completely change the drawing. ( I see a couple people doing this and I can't figure out why.)

To add lumps and wrinkles

To turn curves into straight or mechanical lines

To make the negative shapes smaller or thinner

to tone down the life of the original