Are jumper wires just wires with insulation cut off on both ends?
If you are connecting to actual female pins, it does help to have the right sized male pin crimped onto your jumper wires. But if you're just using them on a breadboard, bare wire ends are fine. Just make sure to cut the wire with diagonal cutters, not scissor-type cutters, so that you get a nice pointy end. The shearing action of scissor type cutters can sometimes roll the wire end enough to make it snag in the breadboard.