Ok, so this is a subject that needs to be beaten to death. Not just for newer players, but seasoned players as well. I cannot tell you how many times level 75's from my own Linkshell get aggro in Sky...it makes Baby Jesus cry it really does.
There's not really any specific method to avoiding aggro, there are just several things to remember. I must encourage you to practice, avoiding aggro is an essential skill that will save lives. If you want to become a Zen Aggro Avoison Master (yes I know Avoison isn't a word), take a trip to Ifrit's Cauldron with a Mage Job and mine there as long as you can. Because the bombs aggro sight and magic (they have a very wide aggro radius), this is a difficult area to be in. If you can mine here for an hour or more, you will be well on your way to becoming a master.
In addition, try making the trek from your Hometown to Jeuno as a level 1 of any job with no Oils/Powders, and no assistance whatsoever. While Ifrit's will teach you how to apply Sneak/Invis strategically to avoid aggro, this will teach you how to avoid aggro alltogether by positioning. Both very valuable skills.
Ok, so here are the main tips for you to remember. If you think of any more please let me know and I'll add them. Please, please take these things to heart. Don't be that guy that gets several people killed, we all know that guy.
1. Yes, Silent Oils are expensive. Yes, unless you are a mage job in an area without Magic Aggro, you still need them. Don't skimp on them. Sell crystals, level Alchemy, sell your Mithra mule's body, whatever it takes. Don't bum them off your party.
2. Silent Oils should be first on the list, Prism Powders are equally important, but you'll find that a stack of powders will go farther due to fewer mobs aggro'ing Sight (depends on area).
3. That mage in your party is not your personal Sneak/Invisible *****. Buy Oils and Powders so that you can be self-sufficient. You don't still breastfeed do you? There's nothing worse than a party member that thinks their mages should follow them around because they want to save some money. If you forget Oils/Powders, ask nicely for Sneak/Invisible. Use complete sentences. Do not simply say "sneak plz", or "sneak".
4. Never, ever use /follow in an area where ANYTHING aggros. Don't fuc[/i]king do it. You will be better off to never use this command, really. Remove it from your vocabulary. If you absolutely have to, stop in a safe place and tell your party that you need to go afk for a few seconds.
5. Don't go afk while traveling, stay with the group. There are few things more annoying than just getting to your camp, and one member in the party saying "wait plz, i dont have map", or "im lost someone come get me".
6. If you don't have a Map to an area and you get seperated, [i]look at the Map anyway. When you select Markers and hit left or right a couple times, you will see your party in relation to your current position. Blue dots are your party, turquoise are Alliance members. Every map starts with A-1 in the upper left hand corner, use this knowledge and <pos> to figure out where you and your party are. I'm sure you know the alphabet and you can count.
7. The second you see your Sneak/Invisible wearing off, take note of what is around you. You now have seconds to find a safe spot to recast or use another Oil/Powder. Don't keep walking, find a spot away from the monsters to recast. This is your #1 priority.
8. Invisible can be reapplied without losing Invisible as long as you do it yourself. This is true for both the spell and the Powder. If someone else is casting on you, you need to take it off first. You can reapply it while laughing in that Goblin Gamblers face. Sneak however, must be taken off before reapplication no matter what.
9. Monsters have what is called an "Aggro Radius". This is a circle projected out from the monster in which the monster will aggro if it's conditions are met. Learn the aggro radius of monsters in the area, the more you learn the more prepared you will be.
10. If you are with your party and get aggro from a single monster that your party can easily kill, go ahead and do it and apologize profusely for the aggro. Why? Because you just made the other members of your party waste an Oil/Powder to help you.
11. If you are seperated from your party and get aggro from something you cannot kill yourself, Call for Help on the monster and die in a safe place if no one is near to help you. Don't train, and don't di[/i]ck around. Aggro happens no matter how good you are, but don't get other people killed.
12. Don't panic, there is life after xp. If you get aggro and can't kill the monster, chances are that you're going to die. It happens, life goes on, yadda yadda. Don't spam your Party chat with "OMFG BATZ!" or "OMFG BATZ AND GOBLINZ!". We can see that you are rapidly dropping in HP, that is very unfortunate. We'll notify your next of kin.
13. Don't bring 2 goddamn Oils and 1 Powder. What is that? You are going to run out. Bite the bullet and buy another stack. Why? Because I assure you that you're going to use them eventually anyway, why not look cool by being prepared?
14. If you are going to Sky, bring a full stack of Silent Oil no matter what job you are. Mages: you cannot use your Sneak/Invisible spells here, you [i]will get people killed from Magic Aggro. I know it sucks to have spells that give you the same effect for free, but you can't use them in Sky. Just trust me on this one.
15. Silent Oil and Prizm Powder last longer than the spell equivelent 99.9% of the time. These things rock, really. The spells are very unpredictable and can be difficult to use. The items almost always last twice as long (there are always the duds).
16. If you are in an Alliance, don't fall asleep dammit. Yes, you have 17 other people with you. Yes, you are a force to be reckoned with. That does not mean you can mess around and download **** while you are on the mission. Stay alert and keep your hands where I can see them.
17. If you don't know what a monster aggros to, look it up here. If you can't do so, ask your party if they know, they'll need to know anyway. If they don't know, ask your Linkshell. Don't have one? Ask a buddy. No friends? Call a GM and ask. Don't test by running up to the monster and seeing if it kills you.
18. A Rabbit exists in almost every zone that can kill you. This is the mantra you should remember when using your Zen Avoison skills.
19. You cannot avoid aggro from a Sound Aggro Monster by staying perfectly still. They will aggro the sound of your breathing, heartbeat, and farting noises.
20. While all monsters have an Aggro Radius, Sight Aggro mobs only use a fraction of this circle in the form of a conical area directly in front of the monster. How big of a line of sight depends on the monster type. This means that you can slip past monsters that aggro Sight only by simply moving behind them...out of their line of sight. Because it's going to be better to use Prism Powders anyway, use this information primarily for True Sight monsters.
21. Ah True Sight...how you will hate these monsters if you haven't discovered them already. True Sight means that you cannot avoid the monster by going invisible...they will see right through it. For these monsters, you must use your Super Mega Happy Ultra Ninja Technique to slip by them...take special note of point #20 which describes line of sight.
22. True Sound? Yup! There are monsters that can hear you even if you have Sneak on. The most memorable monster type is the lovely Fomor (this will only happen if you have too much Fomor hate). Monsters that have True Sound (while rare), can be fairly tricky to slip past. You need to pass them while remaining as far away from them as possible. Often times, you will find that you may just have to kill them rather than avoid them. This is where staying with the group becomes key.
23. Blood Aggro. Undead monsters will aggro you through Sneak/Invisible if you are in yellow HP or below. This applies to Ghosts, Skeletons, Undead Mutts, etc. When moving through an area with Undead, always always remain in White HP.
24. You should realize this fairly quickly, but you must apply Sneak first, then Invisible. Invisible wears off if you use any Job Abilities, items, or cast any spells. An important note though, is that you CAN rest while Sneak/Invisible. This is exceptionally useful if you are a mage that is running low on MP.
25. Deoderize is not just for making Galka smell better! Let me blunt and clear at the same time: No monsters aggro scent. Zero. Many, many monsters will track you by scent though. That means if you Bind Mr. GoblinThatWantsToMakeAWomanOutOfYou and run for your life, he's still going to find you, even if you cast Invisible. He tracks your scent even when you are out of sight. This is where Deodorize comes in. If you run out of sight and around a corner for example, you can cast Deoderize, then Invisible, and Mr. Goblin should not be able to find you.
26. In addition to the previous point, you may hear talk about running across a body of water to lose Aggro. This isn't made up! If you get aggro in say, Boyhada Tree from a Crawler, running accross one of the streams can and will make the Crawler lose you because they track by Scent. (And water covers your stink). Sometimes they'll lose you immediately after crossing the stream, sometimes it takes a couple passes. This is incredibly usefull for links, or unwanted aggro.
That's all I can think of for now. I assure you that each one of these points are important, they aren't ranked by number. This is really, really vital. Avoiding aggro makes everything go faster, and it makes you look like a knowledgable person.
Thank you for your time, happy playing.
Edit: Added some additional points, I'm going to try and reformat this to make it more readable.
Edited, Wed Nov 2 19:10:32 2005 by Stunted