At my office, there is a kitchenette with six coffee urns and one very simple rule: if you empty the urn, you start a new one. See also:
Obviously there are various factors here. If you empty the urn, and someone else saw it happen–or if you empty the urn when you are running late for a meeting with your vice presiden, these things can influence your decision making.
Likewise, if you are pouring your first of several cups of coffee when the urn runs dry, I suspect that you are more likely to make another pot than if you are drawing your final cup of the day. This is Economics 101 stuff: if you expect to benefit personally from the extra effort, you are more likely to do it.
Lately, some folks at work have been introducing other incentives to increase the marginal cost of not making another pot. One person has been labeling the urns with the time of day when the pot was made. I’m not sure this is the right approach. When choosing between urns to refill my empty cup, I assume that the urn with the later time on it contains more coffee (and thus decreases the likelihood that I’ll need to make another). The coffee tastes awful regardless of its age, so freshness isn’t a concern (those who want fresh coffee will buy it from a coffee shop).
I think the ultimate solution is a combination of access restriction and public shaming. Require employees to swipe their badges in order to pour a cup of coffee, and display the photo/name of the last person to pour.