It's fun trying to save fuel between Hong Kong and Beijing where you're given a cruise level 10,000ft below optimum and descent to FL187 300nm out..
i'd be interested in seeing something like a fuel bonus system where bonuses are paid for not exceeding CFP trip fuel burn up until the missed approach point with the caveat that you shall carry not less than CFP fuel (being int'l we have to have an alternate) and missed approach fuel burn is excluded. Results are then deidentified and averaged across all crews each month.