PLD is the Grand Daddy of tanks for 3.0 and every skill they got was a welcomed addition to their arsenal. Their rotation is far more interesting instead of being 1 -> 2 -> 3 -> repeat like it was in 2.0

PLD rotation is as follows

FoF/BB -> Enimty skill of your choice* -> Spirits Within -> Fast Blade -> CoS* -> Riot Blade -> Sheltron** -> Goring Blade -> Fast Blade -> Savage Blade -> RoH -> Fast Blade -> Savage Blade -> Royal Authority -> Repeat while using CoS/SW and Defensive CDs off GCD.

*If you used CoS as an opener your doing it wrong.
** If your still having trouble solidifying agro at this point throw out the Shield Swipe you get from Sheltron after Goring Blade and do this only at the start of the rotation. If thats still not enough then do RoH combo first instead of Goring.