In film openings, there are three basic structures which are: a narrative opening, a discrete title sequence and titles over blank screen.
A narrative opening is when the movie begins with the titles running throughout. This effective because as the setting is revealed in the opening, the titles also appear on top of the scene. However a discrete title sequence is very different. This is when the titles are separate from the narrative (storyline). Titles over blank screen is when the titles are simply played over the a blank screen which is slightly similar to the discrete opening. Although this is very simple, it can be very effective for openings which include ellipses, quick cuts or photographs. There is also a fourth style of opening called a stylised editing is when a title sequence uses many special effects from editing to create an exciting opening. A great example of this is 'The Taking of Pelham 123' which uses stylised editing to match the narrative. This gives a very modern look to the opening. I think this is very effective as it produces a very interesting opening, however, this type of opening may not suit all films.
Here is the opening of 'The Taking of Pelham 123' below:
In my opinion, the narrative opening is most effective many effects can be used when the titles appear over the narrative. For example, a passing car could sweep away a title.