CTM/IWT - Need advice from the pros.

[luxlunae]

I personally spam the key, and enjoy the circling about of the target in pvp.

This. You want that confusing annoying movement going on in pvp, messes with them targetting you and getting casts off.

In pve I generally use a quick tap of my down key (movement slave only) whenever I want them to chillax and stop moving. This will stop the movement while keeping them in range of whatever they are currently attacking. I also have a /follow macro on a quick to hit key that I use if they are running off after combat.

[Ualaa]

I've got quite a few toggles in my set up.

When I press my G6 key (G15 hotkey), it toggles off the "Melee IWT" mapped key.
Which is the one that is called, as part of my DPS spam for melee toons.
I like to disable this, when I want my toons to not move from their location...
For example, on the ground floor in Stonehearth Bunker, or at the top of a tower as I wait for the tower to burn.
By disabling IWT (the melee version, which is imbedded into my spam keys), I know my toons won't run out and possibly fall off the edge.
That gets me Howling Blast (Frost/Death Runes) and Death Coil (Runic Power), but prevents Necrotic Strike (Unholy Rune) and Frost Strike (Runic Power) from going off when targets are out of melee range.

I like that I have the ability to toggle on/off my melee toon's IWT Spam.
Without changing the key I'm spamming.

Everyone will find a system that works for them.
And you'll tinker around with suggestions others implement.
Your methodology will improve over time.