You're going to go out to eat anyway, so why not earn frequent-flier miles at the same time?
All the major airlines offer dining programs. They are free and generally earn three to 10 miles per dollar spent. You call the airline's dining program and register those credit cards you will be using.
Then, when you are presented with your bill, simply charge your meal as you normally would, using one of your registered cards. When the charge goes through, the miles land in your account automatically.
There are no special cards, or coupons to remember, so this is a simple way to earn miles. The airline will send you a booklet with the participating restaurants and the credit cards they accept.
It is a good idea to ask for extra copies of the booklet - one for the car, briefcase, etc. The programs also run specials with bonus miles for specific restaurants or new restaurants.
Save your restaurant receipts until the miles show up on your statement - generally 60 days.