Batting order
Have your power hitters first and your weak batters last. When you use your power hitters, try to smash the ball. With your weak hitters, they are usually fast so do not try to kill it.
Easy doubles
To get doubles consistently, get your timing good enough so that when you hit the ball it says "Perfect". Then, aim your towards the opposite field and hit the ball. If done correctly the ball should one hop the wall. The only players that should not make it are the ones with one star for their speed. If you have someone fast (for example, Grady Sizemore), you can get a triple.
Home run almost everytime
Press Turbo, aim Hit Up, and press Circle.