i've heard many concepts in regard to extra time, the best i reckon is as follow.
extra time, first try wins. a team can still go for their field goals and penalty shots, but that will not win the game. instead, they will only count towards the final score. at the end of the 10min (or however long extra time goes for) and there is no try scored by either side, the team with the highest final score wins. otherwise, it is a draw.
that will encourage a try to be scored, rather than a heart breaking one pointer.