A must have in your kit
This is an extremely useful tool that belongs in every model builder's bag of tricks. With markings and instructions for use on three different scales, this comes in very handy when laying out curves on any layout or diorama. I personally used this to lay out aircraft taxi lines for a number of dioramas and found that it was indispensable.
Flexi Edge
This is a great tool to use for marking roads and making parking spots etc, it allows you to curve roads and it has the right measurements on it for HO, N, O scale. Use with woodland scenic striping pens and you have a real looking road on your layout.