Using frequent flyer miles (SkyMiles) on Delta is easy once you've accrued enough miles for award travel. Since Delta and Northwest Airlines have now merged, miles from Northwest can now be used toward Delta flights as well. Delta SkyMiles can be used for the entire ticket purchase or part of it. There's no fee for using your miles and no blackout dates either.
Log in to your Delta SkyMiles account using your SkyMiles number and PIN at delta.com. If you do not have an online account yet, you can create one using your SkyMiles number.
Search for flights. Then select flights that are marked "Pay with Miles eligible."
Choose from the list of "Pay with Miles" options in the "Trip Summary" page. There you can select miles, money or the combination of both.
Continue booking your ticket after you have made your selection.
