If you use the Hold gamepad style you can use L1 and R1 while holding L2 or R2 to cycle between targets. I prefer to just use the left and right D-pad since it puts a temporary target and you can tag other enemies with one hit of your combo and return to your main target after, or you can hit X to make that target your new main target. It takes some practice but I think it offers the most versatility.

In the options menu there are also targeting filters that you can set. You will be able to swap around with L1 + a button and customize each filter so you could have one that targets only enemies, only allies, etc. If you do this you may want to turn off the auto-filter that changes as you draw and sheathe your weapon.