How to cut larger rolls down to size?

[txpatrol 1]

So I just got a sample roll from 3M and it's way too big for my 24" cutter.

What tricks do you have for cleanly cutting a roll of vinyl down to size?  I've tried searching - who would have thought the words "cutting" and "roll" would show up so many times on this site. 

[Dakotagrafx 7,297]

power miter saw

[Alien 11]

For rolls with no more than those rolls have on them I use a razor utility knife it makes the edges a lot cleaner. Or cut off strips as needed to make sheets.