how can a film opening attract the audience?

In order for a film opening to attract the audience, it could use a title sequence over moving images rather than a title sequence over still images.  The reason moving images is more effective is because it attracts the audience more (when something is moving you are more attracted to it, than if it is still and boring).  During the title sequence in the film opening, it is better to show the main characters name before anyone else.  This is because the people watching the movie are more likely to be drawn in when seeing a name like "Liam Neeson, or Jake Gyllenahaal" rather than seeing the name of a director they don't know of.  For example the movie "taken" shows Liam Neeson's name before anyone else.

A really good way for a film opening to attract the audience is to use foreshadowing.  This may be a hint of what will happen later in the film.  The reason foreshadowing in the film opening is effective is because the audience get an idea of the event that may happen, and they will desperately want to carry on watching to see if that event actually happens, especially if it is something dramatic.  For example in the film opening of "gone girl" Ben Affleck says he wants to crack his wife's skull.  Knowing the plot already "his wife is murdered" the audience will get the idea that Ben Affleck is the one who killed his wife, however they are not sure of that so they will want to carry on watching to find out.  Another good example is the movie "Non Stop", in this film opening Liam Neeson is shown mixing a cup of alcohol with a toothbrush, this suggests he is a crazy alcoholic, and it is probably him who will hijack the plane, however the audience are not sure, so they will want to carry on watching to find out.  

Another way a film opening can attract the audience is by showing a strong relationship between the film opening and the genre.  If the audience are taking 2 hours or so of their time to sit and watch a movie, it is most likely that they are interested in the genre, weather its horror, thriller, comedy or romance.  When the audience get a strong suggestion of the genre in the film opening, they will be very keen to watch the rest of the movie.  For example, for someone who likes action movies, they would be intrigued by seeing gun shots in the beginning of the movie.