Dude! Are you seriously asking this crowd whether it's worth using a FF program? Really?

If you expect to continue flying 6-7 times a year, including internationally, and you'd like at least some of those to be in business/first class, then I suggest you sign up for a FF program (or two) and try and be loyal to it (or both) for at least a year or two.

As for other ways of earning miles, I've never eaten out, or eaten at a particular restaurant, just to get miles. But when I do get miles for eating out, or renting a car, or staying at a hotel, or buying my wife a present, I'm happy to take them.