Research Into Title Sequence

Film Title Sequences are essential in establishing the genre of a film, as well as showing what direction the film is heading in.

An example of a successful title sequence was se7en - which went on to influence future title sequences because of its originality.  David Fincher chose Kyle Cooper to direct the sequence who's attention to detail saw the sequence become an iconic opening.
The director intended the sequence to show inside the killer's mind as he constructed his diaries and books. As well as this, the sequence displayed the cast of the film and made the dark themes of the film easily identifiable.

It is also common for title sequence of a film to put the audience in a certain frame of mind and to portray an idea in a certain way, without necessarily revealing the narrative of a film. For example, in 'Run Lola Run', the themes of time is shown with the multiple shots of a clock.

There is also a drug theme shown in the title sequence because of the unusual psychedelic feeling the title sequence shows.

This establishes the themes that the film contains without revealing details about the film's plot.
You could also relate title sequences of films to an analogy about the similarities between film and literature. For example, the narrative of a film is like the story from a book, whereas the title sequence of a film is relatable to a poem because they both often express thoughts, themes and ideas.