Taking Advantage of Besieged Guide

These days what with Level Sync, Abyssea, Burn Parties, and MMM, it can be a daunting task to keep your Magic Skills capped. It is very important to keep these capped for the main reason of resist rates. The second reason is spell interruption, something a Paladin seems to get the most out of, while it is very nice to have when solo in a pinch. Still resist rates are almost always more important. As a Black Mage who solo's a lot I can not stress the importance of keeping your Elemental, Enfeebling, and Dark Magic capped, When you use that Ancient Magic and it gets resisted 50% you usually end up dead while solo pets. Besides noone wants a gimp skilled Black Mage doing half the damage it can in any and all endgame events (You know those things you are sought after so much for, no not that exp party you never get invited to past 50's) 
Now that we have an understanding for the extreme need of keeping this capped I'm going to better explain to you the method's of keeping them capped. There is the fast route and the painfully slower yet still get decent experience route. 
First the fast route will be explained, I mean after all you know thats what you care for the most. 
Besieged
Find out when these are and make sure to go to them. This is by far the fastest route to skilling up for us Magic Users, the bonus of xp and ISP is a nice perk for our efforts of keeping skill capped. Follow this outline for skilling up each type of magic. 
Divine Magic: This can be the most tricky one to raise. The magic involved is few, mp expensive, and some have large recast times. Just Use Banish and Flash on any mob, careful with Flash I wouldn't start using it unless someone else is using stronger hate tools than you. 
Healing Magic: This is an easy one to level, you simply cast Cure and Cure II on any General and you will get skill ups even if curing for 0 HP every time. 
Enhancing Magic: Much the same with Healing Magic you just spam Protect and Shell on a General, even if the spell hasn't worn off yet don't worry about that just cast Protect every time the recast timer resets to ready. 
Enfeebling Magic: Here is where you stop healing Generals and giving them mini defense boosts. Your going to be finding an engaged monster someone else is attacking and just spam Dia on them. Just cast it over and over, the mob suffers a defense down effect constantly cause your constantly casting every few seconds and it does a little damage that improves your exp accumalation. 
Elemental Magic: Stone I Water I cast simultanously as each of their recast timers reset, just make sure to use on a monster that is already engaged cause even though they land for 0 damage you will die if someone else doesn't have the monster's attention, beyond that don't worry cause 0 damage isn't going to give you enmity and the mob won't care about you until it's defeated everyone else attacking him for real damage first. 
Dark Magic: Bio is your friend. It lowers the mobs attack which is nice allowing the engaged person to take a little less damage, it does good DoT which boosts your experience accumalation. 
Summoning Magic: Have your avatar hit the mob with some Elemental Magic of their own and that will raise your skill even if you just burned your summmoner from level 12 to 75 in a period of 2 days. Its slower than the other magic types but faster than casting an avatar releasing said avatar and then casting it again. Make sure to use both blood pacts to get the most out of it.
Blue Magic: Depending on your skill if you find you are hitting well enough then just treat it like everything else and spam some low level low mp spells. If your gimped cause you level synced for 20 levels and can't hit the broad side of a barn. Set every Magic Based Blue spell you have in your arsenal, they cost a bit more of MP than most all physical spells but its your only way to go about skilling up, save solo'ing mobs at the corresponding levels.