You can either end with soul steal, upskull pressure or just dash in to bair wakeups with footsies. You don't wanna end with upskull pressure in the same position (mix in front and above) and try to avoid quick teleporters (smoke for example).
These are the best I could ever come up with. Easy, good damage, reliable and give you good positioning. I did not consider b1,2,1,4 (or shortened) or f3,4 launchers because in actual gameplay you don't get people who don't know shang's poor mixup, you get people who uppercut you when you go for f4,3,4, pressure, lol.
These do not include a jip or a upskull before that. For upskull + jip + combo you should add about 10% to the said damage. (except for antiairs, duh)
Antiair:
d1 into 1, 2, dash f4,3, mGS into upskull presure if he doesn't have a teleport or something really quick. - 17%
1, dash 1,2 dash f4,3, mgs works alone too - 18%
njp, 1, dash 1,2, dash f4,3 mgs works if you can land NJPs consistently (I for one RARELY landed one when I played this game) - 21%
deep jumpkick, 1,2, f4,3 m gs - 22%
Midscreen BnBs(highest damage, most reliable - 1 meter)
Quick punisher: f4,3,4, mgs, fgs, ex gs, c gs, m gs - 36%
Most damagin punisher ( + morph ) 2,2,1, c gs, m gs, ex gs, c gs, soul steal - 38% + chip if blocked or 41% if landed at the exact height.
Unbreakable punisher:
f4, c gs, m gs, soul steal - 28%
easier version:
f4, c gs, soul steal - 19% - 23% (23% at lowest possible height for soul steal, 19% is 17% combo + 2% chip)
Close to corner:
most damaging:
2, 2, 1, m gs, dash in, f4,3,4, cgs, f43 - 35%
2, 2, 1, m gs, dsah in, f4,3,4, cgs, f4,3 soul steal - 37% + 2% chip
Does same damage with f4,3,4, but it makes it a bit harder, so end it with f4, soul steal or f4,3 (upskull)
Corner:
Adding a "1,2" before the F4,3,4 gives 2% more damage, but makes it harder to land the soul steal and some wakeup attacks may get you before you can block again after the upskull. This is because you don't recover in time and your opponent falls too quickly (height dependent wall game, most people do not realize this)
Pressure hit-confirmable combo:
f4,3,4, cgs, jump kick, f4,3,4, (upskull pressure) -
f4,3,4, cgs, jump kick, f4,3,4, soul steal - 34% + 2% chip
Corner punisher
2,2,1, cgs, jump kick, f4,3,4, soul steal - 39%
2,2,1 cgs, jump kick, f4,3,4 upskull - 32%