Nobody has mentioned the most important tool of all - a good measuring device.

One other thing: You can always cut a little more off.

I would say use a cutter that goes up to an inch or inch and a quarter diameter even then be careful to not over tighten it cause it still might deform the bars. I have a pipe cutter that goes up to 3 inches and it can squeeze a set of handlebars almost flat, I don't use that one on bike stuff, it could cut a frame up pretty cleanly though.

#1 rule when cutting anything is measure twice and cut once because you can't add material back on once you cut it off