Muji has the best stationary products to offer. You can begin with exploring its storyboard notebooks which has its pages duly recycled, thin and are off white in color. And if you don’t like neon colored post-it notes, Muji Singapore got them in neutral colors just for you. And do you know about the erasable rollerball pens that can both erase and write well as an eraser is equipped to the cap so that you can erase your errors like with a pencil.
You can also try the colored markers that are small enough to fit in your palm. May not be easy to write with but serves best in portability and is simple and cheap enough to use.