If you're level 11 I guess you have all the facilities up to max. Means when you tank you get to save up all the reds and greens that come every 4 days. Also get to sell the free academy player that you get every 12 days so money comes in.
Try and build up as young a team as possible, so the players gain more from training and playing and don't lose it all when promoted.
It's the best way to play this game IMO, means you are never short of packs and you can hold onto players for far longer, almost like a real football game!!!!
As for the actual tanking, I always try and win the first 10 games, makes the rest of the season more interesting as it can be a real sweat getting that 8th place or worse when you have points up on the board, plus you get the blue packs that go with it.