In most games, professional players use keyboard and mouse instead of a controller.
One reason for that is the main point of this guide:

You want to be able to do everything at once.

In Kabounce, sometimes you need to aim a smash mid-air, but doing so requires your thumb to get off the ABYX buttons. This is a problem, because what if you need to jump or spin at the same time? You could take your thumb back to the ABYX buttons and do it, but then you can't aim your smash any more, and until you get your thumb back onto the joystick, the opportunity is propably over... But if you are like me, and you want to play with a controller even though the described problem arises, this guide is for you!

TL;DR
Having important inputs mapped to your controller in a way that does not allow you to fire them simultaneously is bad!

You should change your controlls so that you can activate the following actions at once:

• moving, of course
  
• jumping
  
• dashing
  
• activating the cooldown ability
  
• activating the charged ability
  
• spinning / powersliding
  
• aiming / moving the camera

I will treat spinning and powersliding as one action, because in my opinion you wouldn't benefit from spliting up the controlls, as the game already does so by checking wether you are touching the ground or not.

Let's sort some actions out
That's 7 actions in total, which is a lot, considering you only have 10 fingers to hold your controller!
As the controlls for the basic left/right, forward/backward movement can't be changed and already are in a good spot, we have one action less to worry about. 6 actions to go.

(Annotation: Some actions are not relevant to us: plunger launch (This is the button you charge your boost with when spawning. When using it, you aren't even able to do anything else, so you don't need to worry about that), show scoreboard (not important enough to waste one of our strategically placed buttons on it), player targeting (same as show scoreboard, I personally don't even use it))

(Annotation: This tutorial is for XBOX 360 controllers, but I guess XBOX One is exactly the same, and PS4 only has other names for the ABYX buttons.)


Now let's think about what buttons we can use:
Since we want to be able to move the camera, we need the right joystick, so that's fixed, too. 5 actions to go. However, we don't want to have the problem of having to switch between the joystick and the ABYX buttons again, thus we can't use those. The buttons we effectively want to use are the following:

• left trigger
  
• left bumper
  
• right trigger
  
• right bumper

A problem arises here. We have 4 buttons for 5 actions.

From this point on, it is up to you how you map your remaining actions onto the available buttons, but as I want to state modestly, I think my recommendation is quite clever because it solves the problem of having too few buttons.

The trick I use, is to use the right joystick for 2 actions: the joystick movement is used for moving the camera, and pressing the joystick is (in my version) used for dashing.

(Annotation: I considered doing the same with the left joystick, but I personally can't press the joystick without moving it at least a little, which is annoying because then I have to correct my direction of movement afterwards...)

So here is my complete recommendation for your strategically perfect controller setup:

• jump: right trigger
  
• dash: press right joystick
  
• cooldown ability: left bumper
  
• charged ability: right bumper
  
• plunger launch: A
  
• spin: left trigger
  
• powerslide: left trigger
  
• show scoreboard: Y
  
• player targetting: X

Of course, it is up to you to decide which of the 5 inputs you map to which of the buttons or the "joystick button", or even to the ABYX buttons if it doesn't bother you to have some restrictions on your controlls.

However, I found that (of course, only after getting used to it) my version is quite playable, coordination-wise.

I hope I could help you, please let me know if I did so!