It is of course vital to make sure your Debt Collection Agency (DCA) performs at the highest possible level. Measuring this regularly and bench-marking it against industry standards is vital. Also think about the more intangible aspects of your DCA's performance; professionalism, responsiveness, reporting capabilities, speed of paying out collected monies etc.
You as the client have a responsibility to fulfill in this respect as well. If you realise that the better the quality of the debt and associated information you provide to your DCA, the better their performance is going to be, you'll realise that it is a true partnership between you and the DCA that will ensure maximum return on the debts you outsource to them.
For example the sooner you hand debts over to the DCA the bigger the chances are that they will be able to successfully collect. The more time you give your debtor to pay yourself, the more chance there will be that their financial position deteriorates further. The same goes for providing your DCA with as much information as possible. Previous correspondence, responses, contact names and details, it is all vital to allow the DCA to gain results as quickly as possible and importantly get to the front of the queue of people contacting the debtor for payments. Trust me, you are not the only one.
Oh, and I nearly forgot: as most DCAs calculate their fees based on the age of the debt when it is handed over to them, you can save yourself some money there as well.