I finished up a batch of notebooks. I don't think they turned out half bad. They don't take particularly long to make, just a little fiddly.
Most are 2 signatures with a small set of three. I used card stock, covered in a basic abstract painting for the covers. That way they're soft and easy to slip in and out of a pocket. I used some half-way decent drawing paper from Dick Blick for the pages that way it's suitable for a batch of different techniques.
These things are fun to make!