There are many ways to brush teeth but the most effective way is to use the modified Bass technique.

It involves angulating the toothbrush up towards the gum margins at 45 degrees when brushing the upper teeth and a downward angulation when brushing the lower teeth using small ciscular movements of the brush.  It is best to avoid a scrubbing action as this can cause tooth wear, receding gums and eventually sensitivity. Twice daily brushing is recommended.