Instructions
Examine the stats for the players on each team. Access them through the game's main menu or check the link below. Pick a team that you like that has several players with a swagger rating of 70 or higher. The players with a swagger rating of 90 or more are much more likely to celebrate when a play goes their way.
Start the game and focus on your players with the highest swagger ratings on your offense. As you get closer to the end zone, start passing the ball to them exclusively in case they can score.
Throw the ball to a player with the highest swagger on your team while he is in the end zone. If he is a running back, hand the ball off to him and then run it in. The more impressive the run or the longer the pass, the more likely a celebration will ensue.
Watch the aftermath once a touchdown is scored. The celebrations are all stat-based and happen without player input. If your scoring player's swagger is high enough and the play is impressive enough, the game is likely to have that player dance or otherwise celebrate in the end zone. Players with low swagger are much more likely to simply drop the ball and go back to the bench.