I do these:
Jab>Jab>Roll Behind>F-Tilt, F-Smash
Jab>Jab>Jump Behind>B-Air
Jab>Jab>Retreating F-Air
Some tougher ones (May not work, need good practice/conditions)
Jab>Roll Behind>U/D-Tilt>Any air move
Jab>Jab>Roll Behind>Jab>Jab>Roll In front>F-Smash
Good counters to some people's attacks:
PS>Jab-Grab>D-Throw>D-Air (U-Air if percent is high enough)
PS>Jab>Wait>Jab>Wait>Wait More>PS>Roll Behind>F-Smash (Great mindgame)
Roll Behind>Jab>F-Smash (Does not always work)
When attacked in air: (Can use combos after jab is given)
AD/Fastfall>Jab
AD>Fall Behind target>Roll In Front>Jab (Great for mindgames)
AD>QD(Do not hit target)>Roll Behind>Jab
When recovering: (Can Also Use Combos after Jab is Given) (AD and other Horizontal Movement actions can be taken)
Aether/QD>Ledge (Sweetspot)>Jump Recovery>Land Behind Target>Jab
Aether/QD>Ledge (Overshoot)>Roll Behind>Jab
Fair>Ledge (Sweetspot)>Jump Recovery>Land Behind Target (Quite Far Away)>Roll in Front>Jab
My list of stuff. You can get really creative against a sitting duck