An effective lead for a story is an art unto itself. It needs to be at once broad and specific. That is, it needs to introduce the theme of the story while nevertheless being vivid and specific. As Frances Flaherty puts it, "[T]he specifics they cite must sound the central chord of the tale." A good lead teases and provokes; if it does its jobs well, it will lure the reader in and make them unable to resist reading further.
One common approach to a lead is to use an anecdote. But for this to be effective, it must omit unnecessary detail while putting the story into motion with drama and tension.