If you ever rent cars, AA's bonuses with Avis & Budget can be up to several thousand miles per rental.

AA Dining can add up if you dine out a lot and steer most of your dines to participating restaurants.

You can earn about 750 miles per stay at budget hotel programs in many cases (for example, Choice's stay 2 get 8000 points, where 5000 points converts to 1000 miles). That only works if you limit each stay to one (or sometimes two) nights, to maximize the bonus, since it's per stay, not per night.