For me I have a set order that if my main dies, I go toon2, if that one's dead I go to toon3. I use this macro for my following/focus. Lets say this is the toon3's follow macro.

/target [target=toon1, nodead, help, exists]; [target=toon2, nodead, help, exists]; [target=toon3, nodead, help, exists]
/focus target
/follow focus


So that way if toon1 dies it defaults to toon2 to focus off of.

I use different dps button sets for pve pally, druid and three shaman vs the pvp ele shaman and four boomkins. I use /click based for the pve set I'm sure you can find the /click castsequence set up on the site here.

For the pvp slaves I'm doing:

/cast [target=focustarget, harm] [] wrath on one key
/castsequence reset=4/combat/target [target=focustarget, harm] []insect swarm, moonfire on the other key

I have flame shock overlapped with the moonfire/insect swarm one and lb overlapped with the wrath one.

I also have a starfire one set up with chain lightning on it but I rarely use it.

Those are on the four following boomkins. If the shammy dies, I pick up toon2 and by using the [] on the dps macro allows it to "cast through" not sure how else to explain it. I've left it off before and it doesn't allow toon2 to cast that spell. So pretty much renders you useless.

Also, with including toon2 within toon2's follow/focus macro, if toon1 dies I can switch to that predetermined toon2 and toon2 will focus himself and any remaining toons will also then focus him.

Not sure if that helped. But I like it the set up. I used to use /cast=targettarget, harm] but I like the focus better. If ppl don't know your main, which normally they do, they could click the slave and see who they were targeting.

Ivas, Kildo, Plate, Dishe, Spoone lvl 80's
Fork, Straw, Haye, Graass, Bailer lvl 70 pvper's.