Easy money
When the transfer window is open, search for good free agent players with at least skill level 75 and below the age of 30. The higher the skills and the younger the age, the better. Sign them, and offer them the highest wage you can. If your negotiator skills are low, the player you try to sign will reject your offer. Try to re-sign him with a higher offer. For example, if the player's wage is $35,000 the first time, the board will only allow you $45,000 for the player. The player will reject any offer below $70,000.
When you re-sign him for the second time, the board will allow you more than $80,000. You can now sign him. When the player is yours, change his status to "For Sale". Big clubs will be interested in him, and you can get a lot of money. If you manage a small club with a limited budget, do not keep this player. Otherwise, you will not have enough money for other players.
In Manager mode, you will have a 90+ overall team. The Youth Academy in your office will have youth players of about 70 skill level at the age of 15 or 16. You can either play with them throughout or sell them in your fourth of fifth season to earn millions of dollars. Try this with J. Baxter, Rodwell, Bunce, Morris, etc.
Good team in Career mode
Create a club in Manager mode with the maximum budget. Create fifteen or sixteen players with maximum attributes. Set their birthday to 1990 so they are very young. Build only enough players so you have the minimum required for your squad to be ready for your created team. You will now have an invincible team in Career mode. If you do not have too many players, you will not have to pay a lot of money for them. Try to give them as low of an amount of money as possible.
Cheaper players in Manager mode
Sign good players for higher wages, and set their contract length to four years. When they are on your team, go to "Team Management", then "Player Contracts". Go to the good players, and reduce their wage as much as desired. Sign them for five years, and they will accept as long as the wages are not too low.
Faster recovery
If your player is injured and is out for too many days, you can speed up his recovery. Use the player as a sub while he is injured. He will suffer another less serious injury, and should heal in about a week or less.
Fake free kick
While taking a free kick, call the second player by pressing [Pace Control]. Then, hold [Shoot] + [Cancel/Dummy Move] until the meter is full. The first player will roll over the ball, and the second player will shoot the ball.
Dodging free kicks
While the other team takes a direct free kick, hold [Shoot] + [Sprint]. One of your players will jump and dodge the free kick.
Spinning the ball
While taking a corner or long passing from any of the corners, press [Long Pass] and hold a direction button. The ball will spin towards that direction. Note: You can also do a bicycle kick by pressing the direction button to the outside of the penalty box.
Easy trophies
Most trophies can be unlocked in Multiplayer mode. Trophies such as the ones for penalties, the switcheroo, the various ones for scoring and the giant killer are a lot easier if done against a human player.