Notem Notebooks
I go through a lot of notebooks, between sourcing them for photoshoots and being a Virgo who takes notes on everything, I'm pretty picky about what works.
The Notem notebooks meet all my requirements. They come in a variety of shapes and styles, look good enough for shoots, are the right size (not too small to write in), are lightweight enough to carry around in my bag, and the cover is sturdy enough to survive daily use without falling apart.
Designed in Copenhagen, of course. :)
photo from Present & Correct
Find it here