in gcse art, we were given these big ol non-ring hardback sketchbooks and we were expected to make every page Gorgeous. even when we had 10 other subjects to keep up with in one night covering an artist we hate. it was all nice backgrounds, nice titles, interesting ways of showing off the work youre not taught how to do.... we were pressured so much into spending so much time on presentation, and it added up to a whopping zero marks. stupid.
admittedly, nice presentation can be fun, and gives a good impression. but for me, a sketchbook is a working log of research and practices, and as such will be messy, but readable, and crammed with information and attempts that dont pan out and attempts that do, surrounded by stars and all caps 'FUCK YES'es
i still keep sketchbooks, but mine are a lot smaller - journal sizes, usually. sometimes i get these cheap black A4 ring-bound ones for paint work. but my normal sketchbook is A5 and filled with college notes, art notes, poems, thumbnails, doodles, observational and reference sketches, and lots and lots and lots of figure drawings. most of these are unfinished (i work w time limits for gesture) and a lot of them are sketchy and theres multiple tries, theres scribbles of 'this is wrong,' places ive freaked out, sometimes majorly. you can watch me go from complete frustration to being on a roll.
imo sketchbooks are for working in; practicing and taking notes and nailing poses you cant figure out, trying out new things. theyre more personal than portfolios.
im more pleased with my current sketchbook than any ive ever had, its a working sketchbook. definitely the scruffiest ive ever produced.