Sit on the bench with your legs going over the first padded bar and your feet under the bottom bar. Bush your back into the rest and make sure all of your thoughts and effort are on your quads.
Lift by trying to contract the middle of your quads. When you legs are completely parallel, squeeze like crazy and connect your brain with your quads.
Lower the weights back much slower than you raised them and feel the burn all of the way down. DO NOT let the stack rest at the bottom, but instead just before it touches down, begin the next rep.