More accurate targeting tips with a controller...

[Niwashi]

You can configure what the D-pad will cycle between.

check one or the other (not both) of the boxes:
Character Configuration -> Control Settings -> Filters -> Enable Target Cycling
or
Character Configuration -> Control Settings -> Filters -> Enable Customization

The first lets you configure two settings according to whether your weapon is drawn or sheathed. The second lets you configure up to four settings you can alternate between manually by pressing L1 + one of the right-side face buttons. (Someone who only plays tank or DPS can maybe do ok with the drawn/sheathed pattern. For anyone who alternates jobs or plays healer, and so may want to at times target friends during combat and at other times enemies, I'd recommend the four manually controlled filters.)

Once you have customized fiters, of either type, the left and right controller buttons will cycle only between targets matching your current filter. You'll typically want to set the filter to "Enemies" mode during combat, but I'd recommend having another of your selectable filters (or the weapon sheathed one if you prefer using the drawn/sheathed pattern) on "All" mode (which is also the default if you haven't set this feature).

Note: This only affects the D-pad cycling, not what initially gets targeted with the X button.