If you play through Facebook sometime there are buttons at the bottom to watch for boosters and $.
On the main site, there is sometimes a button on the right to watch videos for tokens.

Buying FA's, their value will be parenthesized, it starts at their wage when you go to bid on him. If you can get them for one or two tokens and then sell him you can make $. But my advice is buy only younger ones, over 26 you will have a hard time selling off, and over 30 he might be retiree. So. Buy FA's that you wouldn't mind having on your bench.

Winning matches, keep building all your facilities so you can have max attendance.

Stay in Cup or CL if you get there, those matches each have a good competition pay.