I followed that thread when it first started. Watched an online video that was recommended....
Cutting Basics at Creative Keepsakes. A gridded ruler and a cheap craft knife are what the demonstrator uses.
I went to Micahel's and found the ruler for about $3. Much cheaper than the fancy gadgets that promise to do the same thing. It works for cutting and for positioning the layers. I'm really happy with mine. So is my friend who was stamping with me today.