technique for filing nut slots

All about Nuts, Files and Slotting nut slot files slot to the desired size For example, you can cut a Frequently Asked Questions About StewMac Double-Edge Nut Slotting Files, Set of 6 in My Website nut slot depth I have a set of these from Harbor Freight, and I use them all the time for saddles, but I didn't think they were the right shape for nut slots

nuts and bolts slot I'm really getting them to lower some nut slots in my current guitars, not make new nuts, but it may come to that if I stuff it up!