How to set focus

Either use the in game bindings to assign a key to /focus then target something and hit that key. Or create a focus macro:

Code:

/focus

and use that. To focus specific characters you can either use Unit IDs (UID) like party1 or party3pet, or something like targettarget (your targets target). eg.:

Code:

/focus party1

For a more specific use you can set the target to a specific name... assuming your main is called 'Main' your alts could use:

Code:

/focus main

as their focus macros.

Personally I use a series of macros bound to F1-F3 (though I only box two). Each contains the name of the unit they should focus on when its hit.
Mugnin has F1:

Code:

/clearfocus

F2:

Code:

/focus Hugnin

F3:

Code:

/focus Madnin (my Trail account priest)

While Hugnin has F1:

Code:

/focus Mugnin

F2:

Code:

/clearfocus

F3:

Code:

/focus Madnin

Madnin has the same idea...
Clearfocus - removes the focus, otherwise when you change leaders your new leader wants to follow the new follower when you hit tab.

Then when I change leaders or first create the party, I hit F1 (Mugnin as main) then hit tab: (F2 for Hugnin, F3 for Madnin)

Code:

/follow focus

I also spam (when I don't forget) Tab after combat, FD or swimming-- all of which have been known to break follow.

All my skills that take an enemy as a target then use this format:

Code:

#showtooltip /assist focus /cast <spell>

The mains get a message about an unknown unit (because they don't have a focused target), and the others cast on what I'm aiming at.

Hope that helps.