A china graph pencil or water based felt pen or even a pencil can be used to mark out model making materials.

A compass cutter is used to cut circles in paper and light card. It can be adjusted to cut a variety of accurate sizes.

A roller cutter is used to cut curves and arcs in paper and card. A cutting mat should be placed below the card and pressure applied to the cutter as it is moved forwards.

Paper cutters are used to cut card and paper very accurately in straight lines. These pieces of equipment are very safe as the rotating cutting disk is positioned inside a housing.
A range of cutters are available but the most effective are the large, high quality versions. Small, lightweight versions are cheap and capable of cutting paper only.