To make the days go faster and have all the work done quicker, hold the Right Mouse Button.
Free resources
Use the Merchant to trade away all of a single resource. You can continue trading it, even if you have 0 remaining. You can use this trick to get free supplies from your neighbors.
Quick neutrality check
You can not send a Saboteur, Diplomat, Spy, or Merchant to a territory if it is not owned. If these options are not available for a territory, then it is neutral.