I wouldn't bother with "look and feel" too much on a double-spaced
document: This is a choice for easy of correction remarks, and has
nothing whatsoever to do with "readability".

Well, theses/dissertations must be double-spaced but one would certainly
want those to look as nice as possible. And I consider "look and feel" in
the double-spaced documents that I require my students to submit. But I'm
not particularly picky about it, and this exact comment would not occur to
me (I'm just hoping for a title that doesn't merge right into the text,
visually).

Daiya