Using Heavier Gauge Wire:
This link can be made with heavier gauge wires but those wires are more difficult to spiral nicely. Many times the center becomes teardrop shaped. There is a way to avoid that. However, this technique should be done only on solid or filled wires, not plated ones. Only a round nose pliers is used for this technique. This technique was not done throughout this tutorial.
The wire on the left is cut normally with a flush cutter making a flat cut. The wire on the right is cut at a sharp angle.
Grasp the very tip of the wire with a round nose pliers. Make a curl in the end of the wire around the very tip of the pliers. Do not remove the pliers but shift them around so you can lap the tip of the wire. Notice how the tip of the wire on the right seems to blend into the curve while the one on the left does not. Also, the one on the left took more pressure on the pliers to continue the spiral over the flat end, therefore denting the wire. This will get covered up as the spiral progresses, but still can show a bit.