Continuity Editing - The clear stablishment of 'cause and effect' plotting , which shows a characters motivations and helps to unravel an interesting story that proceeds logically and steadily.
Enigmas - An enigma is something difficult to solve, like a puzzle within the film. It is usually ,in thrillers, something that the main character has to try to figure out to deafeat the villain before the film finishes.
Red-herrings - A Red-herring is something that misleads or distracts us from the truth. For example in North by northwest the red herring in that film is Eve Kendall, she is working as a double agent for the government and misleads us when at first she helps Roger Thornhill. Then it seems to us that she is working with the villains, but in reality she just had to pretend to be working with them to be able to bring them down.
Cliffhangers - A cliffhanger is usually the part of a film where the main character is in a precarious or fdifficult situation or are confronted with a shocking revelation. This is what will keep the audience interested in the film as they want to watch the situation unravel and be resolved.