This site has helped me with slider trends among the developer created NPCs. http://www.truancyfactory.com/mods/skyrim/skyrim_characters.html
I was able to make a half decent Nord borrowing some ideas there. Haven't tried Breton, but I think Aerin and Sam Guevenne are probably good places to start for males. Maybe Lisette, Mirabella for females.
I would start with Cynric Endell or Sam Guevenne. Sam looks a bit weird in CC, but he is quite good-looking in the game.
Making a good-looking female Breton is easy. They are cute by default.