1. Get your scout find good CB players. A good CB players should have the following important attributes.

CB Player Attributes

• Speed (>70)
  
• Ball Winning (>70)
  
• Defendsive Prowess (>70)
  
• Explosive Power (>70)

CB Player Skills (Optional)

• Man Marking.

CB Overall rating (>70). The more the better. Man Marking skill is optional but it is good if you can find one.

2. Get your scout find good LB and RB players.

LB/RB Player Attributes

• Speed (>70)
  
• Ball Winning (>60)
  
• Defendsive Prowess (>60)
  
• Explosive Power (>70)

LB/RB Overall rating (>70). The more the better.

• Always set your CB's to mark opponent's Strikers and Attacking Midfielder.
  
• Your LB and RB should always mark opponent's wingers or RM/LM.
  
• Replace tired defensive player. Always make sure all defendsive players CB,LB,RB fully fit during match

Here are the rules when defending.

• Don't always press S (pass button) to get your player automatically chase and tackle.
  
• Don't always press E (sprint button) to sprint and chase the ball.
  
• Press Q (change cursor) to find the nearest player to the opponent's player with ball. Make sure your player position is in front of / at the side of oppenent's player. If your player position is at the back of opponent's player, your chance to successfully tackle is low.
  
• Short sprint by pressing E towards the opponent's player and immediately press S (pass button) to tackle when your player near enough.
  
• Slide tackle when you are sure to get the ball or otherwise don't do it because you may get Yellow/Red card.
  
• Sometimes, it is good to be patient. Don't always chase your opponent, but run your player to cover open area where you predict the opponent player will go.

I use this strategy and it works 100% most of the time up to Professional level player. For Top Player level, it still work but you need to have a very good player stats to make this strategy works effectively.

Good Luck..