I was told by my instructor to take a breathe before I click the mouse. His reasoning was that we actually spot a lot of the hazards EARLY and click too soon, thus missing out on the points. I have no idea if that's correct, but it did help my scores.
He also suggested double clicking (like you would to open a document) as sometimes, again, you are just out of the ''zone'' where the points are awarded. Be careful though as too much clicking can affect the score I think.