I'm not sure if this system is going to be better or worse than other suggested systems. I personally like it because it's extremely quick to change assist targets and play solo.

Brief summary

1.) Create one targeting macro:

//Targeting macro
/target [mod:rctrl,mod:ralt]Strong,[nomod:rctrl,mod:ralt]Curiously,[mod:rctrl,nomod:ralt]Someotherguy

2.) Instead of including targeting in the spell macros, just reference clicking the button of the targeting macro

//Wrath
/click BT4Button16;LeftButton
/assist
/cast Wrath

//Healing Touch
/click BT4Button16;LeftButton
/cast Healing Touch

Note: I used BT4Button16;LeftButton as an example of how someone using Bartender would set up the system... it took me a bit to figure it out so I'm saving someone some time, hopefully. If you don't use bartender then just reference whichever slot your targeting macro is in.

What this does is separate the casting from the targeting. If instead of using a pure FTL system you'd rather use a system like Ellay has recently presented, then just put that system in in target macro. I believe what I have presented above cleans up our macros and makes them both readable and easily changeable.

One nice feature is the flexibility you have to change things very quickly. If you use different group compositions, then just have a different target macro for each. When changing teams all you have to do is put the new target button in the spot that is called for targeting, and keep the old one in another spot for switching back later on.

For example, usually I will have:
//Targeting macro
/target [mod:rctrl,mod:ralt]Strong,[nomod:rctrl,mod:ralt]Curiously,[mod:rctrl,nomod:ralt]Someotherguy

However, if I would rather use different toons on the same accounts, then maybe I would instead use:
//Targeting macro
/target [mod:rctrl,mod:ralt]Strongstwin,[nomod:rctrl,mod:ralt]Anotherhealer,[mod:rctrl,nomod:ralt]Owltoid

Now all I have to do is put the targeting macro in spot "BT4Button16;LeftButton" and it will use my new targets. When I want to go back to my other group all I have to do is put the original target in the spot "BT4Button16;LeftButton"

When playing solo either nothing needs to be changed, or just move the target macro away from spot "BT4Button16;LeftButton" and it will be clicking on a blank button every time (please note that I use "BT4Button16;LeftButton" but everyone else will likely have their target spot in a different location).