The easiest innovation to accesses immediately is Toland's use camera angles to tell who held power and who didn't. His "super hero" shot of Kane being shot at a drastically low angle is a shorthand for film kids all over the world of depicting a character having power. Another shot of descending down into a night club through the skylight to meet Kane's lover does the opposite effect of the "superhero" shot; through the camera movement alone we are told that she's fallen far from grace.
Another important innovation of Toland's is deep focus. Deep focus is defined as being able to see everything in the frame clearly; foreground, mid-ground, background. Nothing is fuzzy. By using this technique the entire space is active and produces an emotional feeling of powerlessness, a useful tool as the protagonist Kane looses power.
These two camera techniques employed by Toland have been long lasting innovations.