Brushing your teeth is one of the most effective ways of removing plaque from the exposed surfaces of your teeth.
Contrary to what you might think, a gentle brushing with a soft-bristle toothbrush is just as effective (and less damaging!) than a vigorous scrubbing with a stiff-bristle toothbrush.
Your tooth enamel is relatively thin. Years of aggressive brushing can begin to wear away the enamel and make the teeth sensitive. (Remember, the enamel on your teeth does not contain nerve fibres, but the dentin layer underneath does. See the Healthy Teeth page on Cavities.) Brushing too hard can also damage your gums.
For information on electric tooth brushes, or to compare electric toothbrushes vs. manual toothbrushes, you can visit healthyteeth/plus here.