I am designing an essay book: 11 x 17 cm. I would like to give it an avant-garde look, a kind of mix between russian constructivism and the german avant garde in Germany in the 30's. El Lissitzky, John Heartfield, Bauhaus… The best example of what I am looking for is Cristiana Couceiro, two images attached.
So, I am looking for a couple of fonts working well together. I was thinking why essay books usually use serif fonts for body text, and sans —in case of using a sans— only for titles and page numbers. Is there a rule or is ok to use a serif for titles and sans for body text? In both cases, which fonts could give this look?