Drawing a straight line with a mouse is harder than it should be. Even a steady hand ends up with a slight wobble, and on a page full of notes, one shaky line stands out. OneNote's Draw tools have a built in fix for this that a lot of people never discover, because it is not something the ribbon advertises directly.
The trick: hold Shift while you draw
Go to the Draw tab in the ribbon, choose your pen or line color and thickness from the Color and Thickness menu, and select Line from the Shapes menu. Before you click and drag to draw, hold down the Shift key. As long as Shift is held while you drag, OneNote constrains the line to perfectly straight, regardless of how steady your hand actually is.
This is the same convention used in Photoshop and most other drawing applications, so if you already work in design tools, this will feel familiar. If you do not, it is worth remembering the next time you need a clean underline, a table sketch, or a diagram with straight connecting lines.
It works with a mouse, trackpad, or pen
The Shift constraint works regardless of input device. It is genuinely most useful with a mouse or trackpad, where natural hand movement introduces the most wobble, but it works exactly the same way with a stylus or touchscreen if you want a perfectly straight line without needing a steady freehand stroke.
For more small but genuinely useful Microsoft 365 tips like this one, browse the rest of our blog, or if you want your whole team actually using OneNote, Teams, and the rest of Microsoft 365 well rather than just having access to it, our coaching and enablement service is built for exactly that.