I usually don't carry notebooks around, but I almost always have one or more notebooks around where I'm working, including working at the computer. I haven't bought a notebook in years, I've gotten so many for free. Same with pens actually. For notebooks, I usually use A4 and A5 sized notebooks. Most of the time lineated, but I find 5mmx5mm grids useful too. My favourite place for a notebook when I'm working at the computer is placed between myself and the keyboard.

Currently featuring my desk: a A4 notebook from my previous place of employment, turned 90 degrees, situated between myself and the keyboard. Halfway through, top leaf is empty. On my right an A5 notebook (brand "1 Classic" - no idea when it got into my possession), a few leaves used. Top leaf shows the name of a friend in Norway and his cell phone number. On my left, halfway burried under a Krause world coins reference guide, an old 'scribble block'. No lines on the brownish leaves, a low quality recycled paper. Same length as A5 paper, but narrower. On my far left, an A4 notebook from SUN education. Just a few leaves left.

As for pens, I've tons of pens, and just like notebooks, I cannot recall buying one. I'm not very picky with pens - but if I have one that doesn't write nicely, I toss it away. The only thing that I do buy are mechanical pencils - the type you can refill. 0.5 mm is my favourite size. A few years ago, I bought a dozen of them, and now they are scattered all over the house and in some bags. I seldomly have to look long for them.

Abigail