Sometimes which buttons you use to input the aerial can make things easier/harder, but none of them should be too difficult so long as you practice at it a bit. It might be something to consider though, with personal preferences and all.
A is the closest one to the X/Y buttons, so you can just slide your thumb over to it after JCing shine.
C-stick is further away, but many ppl use it for inputting all of their other aerials and want to keep consistent. Just gotta be quicker than with A. I've heard that some people use the Claw Grip (pointer finger kept over the X/Y buttons, so that thumb can be used more primarily for the C-stick), or use the palm under their thumb to make C-stick inputs quicker but...given how comfortable those sound, it might be worth considering another button at that point.
Z uses a different finger, so you might find it easier than A/C-stick with your thumb if that feels off in any way. Keep in mind that you'll end up JC grabbing if you press Z too early (before you leave the ground).