Tips For Racial Abilities

You can cast any racial abilities in your macros. Most of them are best used when you're casting a series of high damage spells
or you're gaining a damage boost from one of your abilities. For example:

#showtooltip Vendetta
/cast Blood Fury
/use 13
/use 14
/cast Vendetta

This will cast the racial ability "Blood Fury" along with the "use" trinkets that might be equipped, then it casts "Vendetta". That would
be a major boost in damage dealt.

Another example would be:

#showtooltip Elemental Mastery
/cast Berserking
/use 13
/use 14
/cast Elemental Mastery
/cast Lightning Bolt

This is a good example of a non-damaging boosting racial used in a macro:

#showtooltip Rebuke
/cast Arcane Torrent
/cast Rebuke

Another for getting out of a stun lock and then stunning your enemy next to you (if you have a PvP trinket equipped):

#showtooltip War Stomp
/use 13
/use 14
/cast War Stomp

Engineers get some of their items with "use" abilities enchanted on them:

/use 6 (belt)
/use 13
/use 14
/use 10 (gloves)
/cast Blood Fury
/cast Demon Soul