DIY Table Numbers

Hi everyone,

I need help with the table numbers. I bought cardstock from Michael's and want to do a layered look with our wedding colors. So I was going to cut a 5x7, 4x6 and 3x5 each in a different color and layer it. But how do I cut the paper with precision? Are there any tools that anyone has used to help cut the paper right? I don't want to have the paper not be cut straight.

Thank you!