what is the quickest way to make gil?

im at the phon coast settlement. the thing about this game, its its slightly MMO style means it takes a long time. i've had it since february and thats why i haven't really bothered to complete it yet!

I guess i should stop buying all the best equipment seems as that gets updated every major event or two beacuase i just end up needing more and more money to get the good equipment each time.