Uh. . .you just have to practice?
If you have a bad habit problem where you're doing the same thing over and over again after a certain action (as you said, rolling after a shffl'd aerial), you need to break it. There's no cure to a bad habit except forcing yourself to perform that particular action differently. Although having people constantly punish you for your bad habits also works rather well.
You can do anything you want after a shffl'd aerial. Literally anything. If it's evasive stuff you want to do, you can wavedash back/forwards, dashdance away, spot-dodge, short hop/full jump forwards/backwards.
Offensively, you can jab 1-2 times, d-smash, u-tilt, shffl another aerial. . .the list goes on. Just think about what you're doing before you do it. Devolving into predictable patterns will hurt you.