Don't forget available buffs. If you're in a guild of sufficient level, stock up, both on buffs and on comestibles. For example, the potion vendor sells Barkskin (+3) pots. They last a decent duration for a +3 Natural bonus to AC, which stack with your Armor and Shield bonus, if you have any. If you're not toting a shield, look for an item that casts Shield. +4 Shield bonus to AC right there, and immunity to pesky Magic Missile to boot.