Take an inexpensive earring and use hot pliers to ease it away from the cheap metal fastening. Take a more expensive silver or gold earwire and pull it through the loop at the top of the pendant part. Squeeze the wire closed with the pliers. Using an inexpensive earring part as a model, bend your own wire to the same shape. You then take a 4mm Swarovski crystal and attach it. Bend your earwire round a smooth pencil and make sure the bead cannot slide off from the wire. You can use the same process for other types of earring, including clip on ones and in this way you can always have high quality metal fixings even if part of the earring is a cheaper variety.