Tombow Fudenosuke Brush Pens come in a 2-pack for less than $5. They look like pens, but instead of a nib they have a brush, which allows you to draw lines of varying widths. They’re a lot of fun to use. — MF

For sketching and painting I favor alcohol-based markers. They let you blend colors like a watercolor brush, but with the convenience of a felt marker. The preferred premier markers are the extremely expensive Copics. An inexpensive equivalent for blendable markers with dual tips (fat or point) are Bianyo. I can paint quickly easily in a notebook using a travel set like these 72 Bianyo markers. — KK

These erasable highlighter pens really work as advertised, at least on non-glossy books. The eraser is smooth and by rubbing on the paper, it produces heat which causes the highlight mark to vanish completely. — MF