I was thinking of a general geometric pattern, one that's not too complex based on the
Paradox pattern (my favourite!) all over the book cover, quite faint: it should look like stamped leather-- recessed version (you've seen an example in Leather Cover 1, first generic covers post). Only the space enclosed by the title ornament would be left plain.
I think it'd probably work better on a nice darker coloured leather cover, though having it as a pattern on a linen cover might be intriguing.
As for what I might do on a linen cover, I'd like to try making something more organic, similar looking to your Leather Cover #10 or Linen Cover #2. I'd probably use the
Mooka pattern for the frame and something else to fill in edges or embellish it; maybe
Crescent Moon. Have to think about it and drawing these things takes time.
ETA: I'm going to be hand-drawing these things; as in pen on paper. I doubt my scanner will do SVG. >.<