Write the length of the story in picas at the end. Indicate all rules, including boxes, with red lines so that they will stand out on the page. If you don't do this, it is easy for the paginator to miss them. When you can't find a red pen, use another bright color. Draw an arrow to the rules and write down the point size.
Most rules are one point.
If you want a certain percentage, include it. Don't make the screen too dark because the reader will be unable to read the text. Make sure that the dummy is legible and complete. If the person paginating or pasting up the page can't read your writing, you might not like the result. When the dummy is incomplete, it hangs up production, which can result in a missed deadline.