Is to always use a 'double-approach' that is not to simply block or punch but to 'block-&-punch/kick' at the same time. Since someone is already throwing a punch (or kick) at you, you may as well 'block & counter' at the same time. He needs some time to recover, but the best way is to go into the kill. One must think in terms of 'combination's or 'strings' of moves (not preconviced but fluid) & that can only come after training. Against Kickboxers & tend to combine 'trickery' with speed. Often he may throw kicks while I'd aim for shins before (suddenly) throwing a shot at his head following by the ribs & a kick to the shin (usually in some kind of random order). However, my advantage has always been speed.