I've read and heared several times about people having big problems with the aiming System on the Xbox one.
This is a very small but strickt guide to simplify the start and see the mechanics behind it.
Aiming itself
The aiming on targets, as you might have seen already, works with the left stick.
The enemy whichs lifebar is shown at the top of the Screen is your current target.
Change between several targets by just moving the stick, it also works while your Charakter is moving.
Range
A big issue for many skills like totems or firestorm for instance, is the range where the skill is placed.
Keep in mind there are exactly three stages of range:
No range (directly next to or above to your Charakter)
Mid range (about half of the screen radius)
High range (courner of the screen)
These ranges work for almost all of the skills, they decide where your totem is placed, where the firestorm falls from the sky, and so on.
Controlling the range
The range is controlled by your left stick as well. It's very simple and well chosen in my opinion:
Not touching the stick: no range
Moving the stick slightly in one direktion: Mid range (also chosing a target there, if there is one)
Moving the stick to the border: high range
How it works for the different skills
If you target a mob with a totem skill, the totem will be placed right next to it (fine for flame totem, ancestral warchief, etc.)
If you target a mob with a projectile skill like Barrage, the target will be attacked directly
If you target a mob (or a group) with a AOE skill like firestorm, the skill will be released right where the chosen mob is. This means, it'll hit the whole group, if your targeting was well placed. If you target a direction with no mobs, or you just jab the stick shortly while casting, the skill will be released at the chosen range without targeting a single mob. This requires some practice, but it works fine!
For some skills like Tornado shot, where you want to aim behind the target for instance, it's quite tricky to get the feeling how to jab your stick correctly, but GGG still works on the finetuning, and the results are improving.
I've tried different builds like Spectral Throw, Flameblast Totem, Firestorm, etc, and after little they've hit quite all that Content i wanted to.
I'll keep this guide updated and hope this helps to improve your game experience and gives a platform to exchange it!