A great way to drive efficiencies within an order fulfillment operation is to, of course, be more efficient with the packing process.
One great opportunity to do that is if you have a certain number of unique sku's that typically ship alone, and at a high volume. Instead of waiting for each customer order to come in for a product that will likely be shipping by itself, utilize some down time to pre-package the products in its shipping container so that when the customer orders do come in it is simply a matter of printing and applying the shipping label to the package.