I find it helpful to put a dot on corners, such as armhole/side seam, side seam/hem, and so on. This gives me something to aim for as I'm tracing out longer seams and is useful when there are multiple lines overlapping.
I know some people like to use a highlighter pen on the lines of the piece they are tracing, but I'm not sure how good this is if you want several patterns from the same sheet.
Good luck!