Pens & Markers
Thickness? Color? Permanent?
Markers and pens are used every session and checked almost never, which is why you often find yourself mid-activity with a dry tip.
The basics: do they write? Are there enough? Are they the right thickness for the surface (fine point for Post-its, broad tip for flipchart)? Are any of them permanent markers on a whiteboard, which will ruin the surface? These are small questions with immediate practical consequences.
Color is worth thinking about intentionally. Different colors can indicate categories, roles, or priority in a group exercise. If you are using color as a coding system, make sure there are enough markers of each color and that the coding is explained clearly. If you have no system, too many colors create visual noise rather than clarity.