for Word
Especially the use of Styles, and avoidance of tabs or extra spaces for horizontal indents, and blank lines for extra vertical space.
I edit in web layout mode - i.e. continuous flow; I have a couple of 'page layouts' that I can use as guides for a couple of reading devices. For ebooks I use a simple template - i.e. not one based on normal.dotm which has far too much baggage.
BR