|This article is grossly out of date. Information expressed in this guide is only helpful for up to Level 75. As such, further information is needed for levels 75-99.|
Throughout the course of this game, it can be difficult to keep weapon skills in a close range to their skill cap. Often, players organize skill up parties. Frequently, skill up parties are also coffer/key hunting parties, but not always. It is not impossible to raise the skill of a weapon by soloing, but it is most certainly more fun to do it with other people.
How to use the charts
Each job can use a different number of weapons. Each weapon is graded A-E. "A" is the strongest weapon skill for that job, and "E" is the weakest. On the left hand side of the each chart, you will see a level, a skill proficiency, and the skill cap for that level. Figure out what the skill proficiency is for the job and weapon you are using. Look at your current skill level for that weapon, and follow down the column that corresponds to the skill proficiency until you find your current skill level. Then, look to the right and see the possible zones/mobs you can fight to raise your weapon skill.
How to skill up
(Please note this is a guide) There are a few different kinds of skills in the game. Offensive combat skills (such as Sword, Dagger, Hand-to-hand, etc), Defensive combat skills (such as Shield, Evasion, etc), and Magic skills (Healing magic, Elemental magic, etc). All three are leveled differently. Here is a guide to a few ways of skilling your skills up to the best they can be.
Skills that are directed to or from an opponent can only give skill ups if your current job would not be capped in that skill if you were the same level as the monster. For example, assume you have a bard with 112 sword skill. Sword caps at 114 for a level 40 bard, so monsters of at least level 40 must be fought for skill ups. Put another way, a level 40 monster can only give a bard up to 114 skill in sword, although a Paladin could gain up to level 123 sword skill on a level 40 monster.
Offensive Combat Skills
Hand-to-hand, Dagger, Sword, Great Sword, Axe, Great Axe, Scythe, Polearm, Club, Staff, Katana, Great Katana, Archery, Marksmanship, Throwing
This is a fairly easy skill to keep capped if you frequently engage in battle during parties, especially in later levels. Most jobs only have one primary weapon they will ever keep up, such as Paladins using Swords, or Dragoons using Polearms. However, some jobs often use more than one weapon, so it's best to keep it up as much as possible. For example, Dark Knights use Scythes, Great Swords, and a few even use Great Axes. Ranger uses both Archery and Marksmanship, as well as tries to keep Dagger and/or Axe up.
However, sometimes these weapons cannot be simply leveled up during parties, either because the job prohibits the player to engage battle (such as White Mage) to make them more effective, or because there are just too many skills to keep up. Skill-up parties are often used to keep these skills up quite easily, though you can solo them up. Soloing is just more difficult, because few jobs can handle it easily, especially with a weapon they don't usually use. Fighting monsters just above the current weapon's skill is usually best, though it means you could have to face Decent Challenge to Even Match monsters to solo later on.
Defensive Combat Skills
Shield, Parrying, Guarding, Evasion
Every job in the game gets Evasion, and most get either Shield or Guarding, and several get Parrying. However, most of these skills are hard to keep up unless they're the main tank most of the time. It is much easier to level Evasion than all other defensive skills because you can get a skill-up whether you evade or take damage, and the chances of anything else happening are quite seldom. All of these skills happen more often with more Agility, so it's better to skill-up with as much AGI as possible. If skilling-up a Shield, use a Size#1 shield (Buckler). If skilling-up your Parrying, try getting one or two Parrying Knives. Don't get the skill too high, though, or you'll have to fight far too difficult monsters longer than you have to.
When trying to skill-up Shield, Parrying, or Guarding, the best thing to do for early levels is to train a lot of monsters (ones that parties don't exp off of), then find a narrow area and switch your target to a monster behind you, then face all the ones attacking you. Doing this will let the easier monsters that you're skilling up off of attack you without you attacking them. For these three combat skills, you need to face the target to get them to kick-in, so doing this is a must. Try to keep the monster level just a little bit higher than that of your skill's current level so it will kick-in more frequently but you'll still get a fair amount of skill-ups. On monsters closer to your own level, be sure to be careful not to let them deal too much damage to you, as death can still happen, especially when you get to Even Match or more difficult monsters.
Healing Magic, Enfeebling Magic, Enhancing Magic, Divine Magic, Elemental Magic, Dark Magic, Summoning Magic, Blue Magic, Singing, Wind, String, Ninjutsu
These are generally easier to skill-up compared to other skills. Healing, Enhancing, Summoning, Blue, Singing, Wind, and String can all be done without the use of any fighting whatsoever. The few others will require you to spam spells during skill-up parties, or cast them once or twice in an exp party assuming MP/hate gives you the freedom to do so. Since most jobs that use magic skills are mages, and most mages have a difficult time soloing, trying to keep Enfeebling, Divine, Elemental, Dark, and Ninjutsu up might require a skill-up party. Other than that, it's fairly simple just to stand outside your Mog House or cast it while waiting for a party. Ninjutsu can be skilled-up by using Utsusemi and Tonko over and over, but since that requires tools, and for the most part Shinobi-Tabi and Shihei are expensive, you might want to use the Elemental Wheel in parties to keep it up. Unresistable spells including Enfeebling, Divine, Elemental, Dark, some Blue, the elemental Ninjutsu spells, and even Healing and Enhancing skills can all be very easily skilled-up in Besieged. Besieged monsters are incredibly high-level and have gigantic pools of hit points. On top of this, Besieged items allowing things like Haste and 2x MP can make this a quicker and more fluid process than any skill-up parties. Expect to get +0.3 to +0.5 skill every couple of spell-casts. This works all the way up to level 75 as any job. Keep in mind, however, some monsters resist all magic or can even be healed by it, so be careful. For Healing and Enhancing skills, just spam spells on friendly NPCs; since they are NPCs, you get much faster skillups than you do casting the spells on yourself or other players.