If you have only one controller, when the QB throws the ball, quickly hit until your selected defender is near the receiver. Hit to intercept.
Two Controller Method by Philli Vanilli:
Player 1 (your profile) - Saints on Rookie
Player 2 (open profile) - Lions to Custom (+20 for all)
Rewinds - Unlimited
For the Lions (on offense), go to the playbook, "Standard Pass" and pick "Inside Cross." For Saints (on defense), go to the playbook, "Man Zone Coverage" and pick "QB Contain."
Player 2 hikes the ball. Wait 2 seconds then soft throw to the receiver (tap button) and it will likely get picked (defensive player doesn't have to be controlled by Player 1). Get tackled and punt the ball back to the Lions. Repeat.
While testing out this method, I had 8 interceptions at halftime.
Achievement unlocks at the end of the game.