For magic you can go to beaudux and camp an afflictor ( Those giant glowing red bongs ) get yourself cursed and engage a mob, I recommend being 60+ so you can afk without the worry of dying. Its a boring way to do it but it gets the job done.
First generate hate on a mob, you can do this by healing next to a fish or a quadav and get its attention, have the automaton engage the mob and make sure the mob is not in melee range of your automaton (Turn around also if you engaged by punching). It will by default attempt to cursna you, at every attempt you'll get re-cursed by the afflictor, now you can AFK until your automaton runs out of mp. As far as attachments go mana tanks, conserver, manabooster ( Will remove 2 seconds with no ice maneuvers ). DAD as needed as mp gets low.
XbobX has a good idea about having a 90 job and subbing pup to get it to 45level skill. After that its kind of a toss up, I believe you can still do castle Zvhal (S) Fortalices till 75 level skill. There's alot of those in the fortress so skilling up shouldn't be terrible, they do die kinda fast if you're doing melee automatons on them but if you have no other choice, and can't get parties to get it skilled up past that point, this would be your best bet ( I didn't get the luxury of exploiting this until late 75 skill levels ).
Once you have Armor piercer and atmas to compound onto it, like Dfoley says, you start punching out serious numbers in abyssea. Now I understand how people say " why do you always talk about burts? " for the level of difficulty ( Not difficult to obtain ) You should make this a top priority even if you're not 89 yet. I've seen you around caitsith, unless you're Glamdring of another server, alot of pups I know on this server have bumped into people grinding for souls and they almost always FLOOR BURRATINAIOS. I would snoop around to see if there are any groups out here, most groups will not charge for the weapon, and if for some reason you can never get lucky with these kinds of groups, you can always solo the T1 > Colorful Abyssite in Visions areas, they tend to be the easiest and try for a T2. Shout in PJueno and offer off the souls or something, I'm certain someone will bite it ( You might even get a few people to come tag along with pops looking to get theirs done as well ). So there is no reason not to plan ahead, for how easy this weapon is to get, it is a total game changer for pup ( If I may be so bold to say ). I'll be as crazy enough to say its a blackbelt for your automaton.