Eye level : This technique is when the photos are taken at the same level or height as the object or person. Most photographers use this technique, so when you take a photo it would be better to take them from different perspectives so that you can get a more interesting photo and make it have a better composition.
High-level : This angle is when the picture is taken from above the photo eye-line. Making the picture more dramatic, because it looks down on the person/character.
Low-angle : With this angle the camera positioned low on the vertical axis, anywhere below the eyeline, looking up.
Bird's-eye angle : This would be looking directly down on the object, giving it an effect of largeness and importance.
Slanted : This is put to the side so that the horizon meets the bottom of the frame at an angle. Giving it a sense of uneasiness or thought. Making you see it differently, giving the object and background a different view & emphasis.
Negative space is in mostly all pictures, if not all. Many times we want to take away that from a photograph, but it's usually what males it strong. Negative space is the space that surrounds the main focus/subject in photo. This space is like a contrast to the main object. So their is balance and the eye knows where to be directed, its important that either the subject or the negative space have a solid color and other have more than one. Usually though, the negative space gives emphasis to the subject, so it's important to not take it away in a photograph.