The tools Bartdude posted are definitely designed to cut this tubing and will make life a little easier. However, in my experience they are not necessary.
I just redid my loop with EK 10/16 ZMT this weekend. Some good kitchen scissors did a great job of making nice clean cuts. It isn't so much about what tool you use as it is making sure you align properly and make one fluid cut all the way through, without stopping. Don't try to cut say 50% through then readjust the scissors or you'll have terrible results.