There are multiple ways of comparing and contrasting structures that each have different implications and dangers.
1. The back-and-forth method, in which every other sentence compares and contrasts. ie: P1- theme -p1 Book A is blah, whereas Book B is blah. P2- theme -p2 Book A is blah.... you get the point, The danger of this method is sounding too redundant, although it does a good job of focusing on the themes.
2. The separate, mixed theme method, in which an entire paragraph is dedicated to each subject, but the themes are thus mixed up within those paragraphs. This method is less redundant but runs the risk of losing clarity of theme.
3. The compare vs. contrast method. This one is fairly straightforward: A paragraph comparing, a paragraph contrasting, and one of synthesis at the end. The pros: It's playing it safe, and it'll work. The cons: It's boring.
Combinations of these 3 methods work as well, it all depends on your personal writing style and the subjects you're comparing.
