This style of earwire has been a bestseller for me for many years. I offer it almost exclusively as an interchangeable earring, which I sell in sets with 5 different pairs of drops.
Cut a 3" piece of 20 ga half-hard sterling silver wire. At one end, make the smallest, roundest loop you can with round nose pliers.
Using your favorite pair of pliers (I use my bent nose pliers with a coating of Tool Magic), set the loop in the jaws of the pliers, close to the joint. With your thumb, coax the wire up and around the initial loop to start the spiral. Reposition the the spiral and repeat until there are 2 1/2 revolutions.
Flatten this spiral. Here, I've used my rolling mill, but this could be done just as effectively with a chasing hammer and an anvil or bench block.
Place the flattened spiral in the jaws of the pliers and bend the remaining wire back at a 90 degree angle. With the other earring in the pair, you will bend this wire toward you at a 90 degree angle. This will create 2 earrings that are mirror images of each other.
Place your round nose pliers just past the bend and using your fingers, bend the remaining wire straight up. This will create the space where your dangle will go.
To create the part that goes through your ear, I use a size 13 aluminum knitting needle, as shown in the photo. I find it helpful to do both earrings at once, to ensure that they are the same length.
Using a chasing hammer and anvil, flatten the top of this curve. This will work-harden your earwire even more and provide the desired "springiness". File the ends and bend them up slightly.