The best way to cut them is with a pair of fence pliers aka fencing pliers. It makes a big difference. The cut is clean and slightly diagonal, so the ends are easier to file smooth. These pliers "snap" rather than cut, and even with my weak grip (muscle and nerve damage rt forearm), I can manage it.
Ebay has them. Here's an example of what they look like:
http://www.ebay.com/itm/10-1-2-FENCE...item337fc21dd9