I don't have any experience with more modern tools, but I can tell you how we did it back in the old days. We kept a roll of soft steel wire (solid-not stranded) on the workbench, stuck the end of the wire into the cable housing, then cut with a pair of good quality 8" linesman pliers. The steel wire kept the helical steel housing from collapsing when making the cut. A quick shake of the cable and the cut-off piece of steel wire would fall out. If working on an inexpensive kid's bike, that is all we did but if it was a quality bike we would make a quick pass of the end of the cable across a bench grinder with a fine stone. Worked well on both the large diameter helical brake cable housing and the smaller diameter gear cable housing. Of course that was in the day before cables had any type of liner.