There are just a few more little things that you learn as you go

Using Trina with items: Using trina's on items can get VERY expensive and should only be used when going to +7 to +8 on High class items, but some people use them from going to +6 to +7 cause there not wanting to lose ro zeny there legit item.

As for items, the better mages have 2 sets of items, just like they have 2 sets of armor. Hp and mp armor goes with hp and mp gear. A good mage should have a set of at least +6/10 hp and mp armor along with either unique or +9 items.

The best unique include Rings of Magic, crystal rings, crystal belts, crystal amulets, mage earrings, lycaon pendants, and other items that give defense, magic power, or hp bonuses. That's about all there is to mages.

There are just a few more little things that you learn as you go such as "a wizard staff +7/56 won't hit for as much as an elixer staff +6/48" or "the level 45 aoe spells actually hit for the same amount or less than the level 33 aoe spells. They just have a much greater range".

Lastly, try to get any scrolls that you need for your mages. People may look at a fire blast scroll for well over 20m or an impact scroll for almost 40m and decide not to get them. They really are worth it!