Rhythmic words and gestures, possession of spell books, and the use of incense or other props. However, the enchanter would have cast the spell in privacy, and it would have already been done before you started your search. Even if it actually had some magical power, you wouldn't find the source.
A long time ago, people had no idea why anything happened. Science wasn't around then, see, and so people made up whatever made sense to them to explain naturally occurring phenomena. When something bad happened to you, it must have been that person who doesn't like you, the one you also dislike so much. How could they possibly cause such misfortune to befall you? Why, by witchcraft of course! Remember Salem? This stuff can get out of hand!! But it's all a giant game of pretend.