Read air dodges and rolls. Because there's a certain amount of frames of when an air dodge is occurred. To punish air dodges, wait till the animation is finished and hit them with an attack or grab them when they reach the ground before they can dodge again.
As for rolls, if you can see the distance of where the roll is going to end, I would recommend either grabbing or a down smash. Because I usually see this as the opponent is either stalling or afraid of you.