Here's a fabulous trick to keep your punch less watered down and for a longer period of time. It's all in the ice.
The trick is to plan the ice right. You don't want to drop a pound of small ice cubes into the punch. Instead, you want to create ONE LARGE, aesthetically pleasing ice block.
It's important because, the larger the piece of ice, the slower it will melt. Also, the slower it melts, the more chilled your beverage will be.