[ERA Chas]

A scalpel, found at surgical supply or model and hobby outlets is the BEST cutting tool-period. Get extra blades and change frequently.
I mentioned the roller in that tutorial I wrote and it's invaluable. Get a 6" wide framer's roller used for adhering posters onto adhesive mounting board.
I'm not so sure about heating the vinyl-I think it contracts again after it is cool. Even when adhered down with contact cement.