My bank of $90 was built mostly by freerols. If you want to do that, you need to identify sites that promote freerols on a regular basis with a restricted field. If you're playing freerolls with 1200 entrants, forget about it. Deposit the money.

I found a brazillian site that was offering weekly freerols at Everest with a prize pool of $100. I made around $60 dollars playing it every week.

Another tip is to try a no-deposit bonus. It takes forever to clear but is great to develop your skills and BR management. Besides my bankrool of $90 I have $50 at CD Poker and $64 at Absolute poker with no deposit whatsoever. After unlocking one of these bonus I intend to transfer my money to the other site and start to play higher in order to unlock the other bonus faster and improve my understanding of the game.