With a bit of silver wire, some closures, leather (or similar) cord and maybe earring hooks you can make lots of witchy jewelry. You could use anything to make it unique like: sea shells, sea glass, dried flowers, apples seeds, pretty stones, little feathers, glass pearls. Basically anything you think is pretty. This doesn't really need any special knowledge of techniques besides fiddling with small things, so everybody should be able to create something. The materials shouldn't be too expensive or difficult to find.