I've mentioned in the past about my struggles with pen and paper - whether it is the friction of getting out the pad and having somewhere to lean, or being an impatient writer who struggles with his handwriting at anything less than a snail's pace.
I like my Lemome notebooks, they are such good quality, but having to carry one in my bag and not always being accessible, is definitely a barrier to quick note-taking.
While sorting some things out to decide what was rubbish I came across an old LootAnime box still containing items nobody wanted. While most of the items were, indeed, heading for the bin I did come across a couple of Field Notes notebooks; small and slim enough to be slipped into even a trouser pocket. They may be branded for the anime RWBY (pronounced ruby, apparently) but I don't see why that should be an issue.
I now have one, with a pen, in the same pocket as my phone in the hope I'll reach for it instead.