There are different rules when shooting a movie. Ask a director as they will most certainly tell you. These rules apply differently to different conditions.
When shooting from an angle, staying in that angle by 30 degrees could make your audience confused. You will want to help them understand why you moved the camera and staying in that scale will not do that.
Because the change that happens in that range is too limited, your audience will think that you made a mistake or will simply fail to understand your decision to do so.
We will want to go beyond that angle so that enough change will occur and your audience will understand it is a different shot showing some other detail.
Awkward zooms will also not work unless that is what you are aiming for. A shot with a different zoom level on the same angle will eliminate the sense of clarity.
When showing two or more characters, you will want them to appear on an axis that clearly defines where the camera and audience are and you will want to preserve that unless you want to make the audience aware of something out of place.
The most common way of applying this rule is in a dialogue where one character appears in reverse (as if in a mirror) to the other. You can also call this reverse shot.
Breaking this rule means you want the audience to be aware of a change in state or something out of balance. For instance, the character may be a thief hiding something and the shot can show the mismatch in axis in a dialogue with a police officer, stating that the character is not having an eye-contact with the officer.
Another example to this could be a character who was once weak gaining power on on another character. The shot could slowly change the angle where the new angle defining the moment in which the power shifts.
An establishing shot defines the scene, and the place and signal the audience that the next shots (e.g., a close-up) will belong to this scene and place.
An opening shot is a technique where a single shot goes on for a several minutes without interruption. For example, this can show a large neighborhood where the story will take place including the places for the individual shots. A director can use this so that the audience can know where a place is relative to the other places.
Mise en Scene (Mizansen)
Mise-en-scene is the every other task that a director has to handle in order to achieve a level of consistency.
This can be deciding which style of clothes to use, or at which angles to shoot. You can call this the planning phase.