I would just like to say that Crown bought gear and pets should not be allowed in PvP. I'm tired of seeing these low level characters with more HP then me because they have paid crowns to buy their gear. It's cool if they want to use Crown Gear for questing and such but against another player it's a little on the OP side. It's pathetic that a level 11 one shot me cause of their pet so I'd like to suggest putting level restrictions on pets so that you don't have low level characters with spells that should be in the hands of a higher level player. These are just suggestions and my opinions, flame me if you wish. I don't care.
Well if you can, try to get a lot of resist and shields here are some tips in dueling that MIGHT help: 1. have awesome resist 2. shield when they start to power up or when they have the pips to cast spell, that way they wont expect it 3. I always keep tower shield in deck so if you dont have a shield for a certain school, tower shield is there for ya. 4. dont speak in pvp! If you do, they can find out your school and shield like crazy. 5. You should block pvp enemy chat sometimes. Sorry if these tips dont work they are just how i win in pvp. I am a knight at the moment so i hope this helps and good luck! :)
3. I always keep tower shield in deck so if you dont have a shield for a certain school, tower shield is there for ya. 
4. dont speak in pvp! If you do, they can find out your school and shield like crazy. 5. You should block pvp enemy chat sometimes. Sorry if these tips dont work they are just how i win in pvp. I am a knight at the moment so i hope this helps and good luck! :)