I don’t want to have tooooooo many gadgets around when writing in my bullet journal or a campaign journal, just because it reduces portability and increases friction.
But these things I’ve found very very useful. I got them on JetPens, so I’ve linked to the product pages there.
I am kind of a perfectionist and I know that it’s okay for journals to be messy and have mistakes but it’s really handy to be able to white-out things quickly and easily.
The Power-Corre is pen-shaped, and you press the tip down to release the white correction fluid, which you can then push around to cover the problem. It dries pretty quickly, and then you can write over it with other pens.
Nakabayashi Magnetic Bookmark Ruler
JenPens: small (15cm), large (25cm)
Rulers are great for making straight lines for calendars, columns, underlines, and other layout effects.
These rulers have magnetic backs and a hinge, which means that they can clip around a page in your notebook. This makes them a bookmark, but more importantly it means that it’s already with your notebook when you need it.
I have a half-dozen of these in different colors, scattered in notebooks and clinging to the metal parts of my desk.