Accessories play a very large role in Last Chaos. If you plan things right, you can spend your time grinding for exp or sp shorter, you can avoid being hit less often, or you can boost your Mp or Hp. It all depends on the situation.
Some accessories should be looked out for are ones that have these bonuses: Evasion Each point of Evasion offers you 1 Close Range, 1 Long Range, and Magical Resistance
Magical Hit Rate and Hit Rate–These stats increase a Mages damage by several-fold. And when it comes to multiplier skills (last chaos gold) like Terra Spear that take your magic attack and multiply it, the damage is increased drastically.
Magical Resistance A stat is really overlooked. This stat will allow you to dodge hits from magical monsters. It should be really helpful later on.
These bonuses are helpful, but are a subjective list. If you find another type to be more helpful, then go ahead and use it.
A quick note is on rare accessories, while most of these accessories are decent, the Rage of Demon and the Eye of Wiseman only offer you a larger mana pool. They do not boost your damage as much as most people seem to believe. Ignore the Tears of Knight or the Chain of Tiger, neither help the Mage Class. All of the others, the Stone of Shadow, the Crest of Rainbow, the Pierce of Wind, the Eye of Spirit, the Stone of Life, and the Origin of Land, all have useful effects.
The best pet to mount for a Mage early on is a Horse. Mages have low Defense and low Hp to start with so, any boosts in either of these areas in a considerable help. Dragon's are great for low level (lastchaos money) SP farming, while it's hard to use a dragon to sp farm after Level 42. That is all; hope it could help you a lot.