The key to understanding the Ninja lies, in part, in understanding its weaknesses. And it has a lot of them, starting with the fact that Ninjas wind up being fragile as heck. A Ninja's durability is about on-par with that of your average caster, as crazy as that may sound; compared to Monk and Dragoon, Ninja is easily the least durable melee DPS class and doesn't fare too well compared to Bards, Black Mages, or Summoners.
That alone is harsh, but it's not the end of their limitations. Ninjas have a rotation that requires learning various combination abilities and then unleashing them, which brings with it a chance to fail. They have no threat dump whatsoever. They also lack much in the way of solid AoE options; their area toolset includes two combination attacks that can hit an area and an AoE that's strictly worse than any single-target attack.
But therein lies the Ninja's strength. For all that you don't have, you do have the option of shredding any single target to tatters at remarkable speed. Just as Black Mage outmatches every other class pound-for-pound on area damage, Ninjas can break down single targets into their component parts with a speed and intensity unrivaled by any other classes. They also bring solid party utility in the form of a TP regen buff, a party-wide damage buff, and a slashing damage buff (useful for Paladins, who have no access to it, and freeing Warriors from the work of applying it). Your TP is functionally nigh-limitless, and you can provide more DPS from range than any other melee class.
It stands in direct contrast to the other melee classes. Your goal is to kill things before they kill you, and you have a lot of tools to do just that.
First of all, before you play much Ninja, you might want to take a whirl on the simulator. The cooldown between Mudra is half a second each, and your goal is to be able to unleash a three-gesture combo between ticks of the GCD, which sounds intimidating, especially when you consider that you have seven different tricks to unleash in any given situation.
It helps once you grasp that Ninjutsu only cares about two elements: how many Mudra you use and which one you end with. Using a single Mudra and then Ninjutsu will always produce a Fuma Shuriken. Ending with Ten produces Katon (AoE around the target) with one Mudra, Huton (attack speed buff) with two. Ending with Chi produces Raiton (single-target damage) for one and Doton (slow and damage field) for two. Ending with Jin produces Hyoton (bind effect) for one and Suiton (in-combat stealth) for two.
In single-target situations, you'll want to rotate Huton, Raiton, and Suiton. Suiton's big use is applying Trick Attack again in combat, which becomes super-relevant only at 50, but getting in the practice is well worth it. Since Ninjutsu is on a 20s cooldown and Trick Attack is 1 minute, this will allow you to get maximum uptime on Huton's buff as well as that party-wide 10% damage boost. If the target is going to die before it's relevant, you can just hit two Raitons between Huton re-applications.
Multiple targets are a bit trickier, since you have options. I don't find Doton's damage field to be terrible worthwhile in PvE, although it has applications for PvP; I tend to favor Huton followed by two Katon shots, then back to rebuff Huton. AoE-heavy situations can benefit from rotating Doton and Katon between Death Blossoms, although Death Blossom is kind of terrible. Focusing instead on hacking down single targets in an instant is an option.
As for Hyoton and Fuma Shuriken, both are highly situational. Hyoton is mostly a PvP trick, although it can have some use elsewhere, such as soloing enemies in leves or briefly controlling something that's heading for the healer. Fuma Shuriken, meanwhile, is useful if you have to stay at range for an extended time. At 25y of range, it's almost at spellcasting distance.
Always remember the rules of Ninjutsu as you work in a combination. Never hit the same Mudra twice, never try to use a skill between your Mudra, and never use Ninjutsu when the GCD isn't going. The first two will produce a rabbit effect for you, which increases your damage by a grand total of zero. The last will simply prevent you from maximizing your overall damage.
First things first: Mug, functionally, is identical to Jump. Again, it's something to weave in between GCD cycles for extra damage. The increased drop rate is nice, but the valuable items in the game don't come from drops. Even the valuable crafting drops are usually those found in chests. Use Mug for a spot of extra damage, and that's it.
Cross-class-wise, you'll have access to Lancer and Pugilist. Blood for Blood and Internal Release are obvious, as is Invigorate. The last two spots are up to you, but I recommend Second Wind and Keen Flurry, since any defensive options you can muster are worthwhile. (Mantra is also useful for similar reasons, but a bit more clumsy and not useful at all if something's already on you.)
It's important to know about what enemy abilities can be silenced and which can be stunned, as Jugulate can perform both functions with a venom swap. If you can silence it, do so. Stun builds up a stacking resistance over time; Silence does not. The heal on Mug is pretty irrelevant, since it deals less damage than even your first weapon skill, so swapping venoms is functionally a matter of choosing how Jugulate will work.
Shukuchi is a fun little trick, but it is not as useful as you might think. Sure, the teleport effect is nice, but you have no upward clearance whatsoever and the ability has a notable windup time. Trying to use it to dodge will usually result in your getting plastered by whatever just hit you. Use it to bypass the occasional scenic hazard, but largely it's a toy.
Last but not least, it's important to stay mobile and flexible at all times. As a Rogue you'll be juggling two DoT effects, a debuff, your Ninjutsu cooldown, your regular weaponskill combo, and other special attack cooldowns. Stay calm and stay focused. At any given moment, you have options, arguably more than many other jobs. You will rarely run low on TP, you can run back and throw daggers with impunity, you have Perfect Dodge, and you have tricks open. Keep examining the situation and determine how best to react based on that. There are no absolute rotations, only priorities to maintain, and when you're prioritizing correctly, you'll be slaughtering targets almost as quickly as they present themselves.
Also, have a tank friend willing to queue with you. There are kind of a lot of people leveling the class right now.
From Eorzea to Vana'diel, there is a constant: the moogles. And for analysis and opinions about the online portions of the Final Fantasy series, there is also a constant: The Mog Log. Longtime series fan Eliot Lefebvre serves up a new installment of the log every other Monday, covering almost anything related to Square-Enix's vibrant online worlds.