The 3 basic structures.
1. A narrative opening with the titles opening throughout it.The title sequence is part of the main film.
Eg. The Stepfather's opening opening makes the audience know who is the main character/killer.
2. A discrete title sequence is a small self contained film that is separated from the actual movie's opening scene.it could be creating a whole different mood and atmosphere all together.
Eg. Seven had a discrete title sequence which portrayed a chilling psychotic issue with extreme close ups. but the actual opening sequence was of a couple in bed.
3. Titles over a blank screen followed by the narrative opening so the music is used to create the mood of the movie. Eg. Donnie Darcko the music builds up and the landscape scenery.
This is when the editing used is in a certain style which usually relates to the film.
Eg. Taking off pelham 1,2,3 he titles move horizontally across like the way a train does.