Try to make the settlement as "credit report friendly" as possible.

As part of the settlement agreement, request to have the creditor remove all references of the account from your credit report. If they wont, ask them to simply report the account as "paid" instead of "settled" and remove all references to delinquency, charge-off, collections, or repossession. Your success will depend on the policy of the creditor that you are dealing with. In worst case, the account may appear on your credit report as "settled" or "bad debt" and reflect references to the former status of the account such as delinquencies, charge-off, collections, or repossession. At least you will have gained by paying your debt off at a discount. It will show that you took responsibility and were committed to paying your debt off regardless of the fact that the debt was settled.