68 mystic will be tough to do so on. Reason being you are more likely to get stuns and the level brackets are from 66-79, most are 75+ so you will get not only high damage vs you but stuns often. The higher level will also crit more often on you.
There are some decent builds on these forums, but the most important thing u will need to do is max your resistances (Theme battlefield wand and shield)
For your jewels you will want crit, HP build can work in pvp like I use but I dont suggest it unless you have a lot of lant and a higher level 75+.
Armor u will want to cap your resists and put some con xeons in, this will allow u to do well in pvp.
For your gameplay style in pvp you will want to play more of a supportive role, stay with party members pop off some heals and use them as your shield since your level will make you die faster. Dont forget a few pew pew's though if your safe to do so ^^.
In any case I wish you the best of luck and enjoy your mystic.
Edited by Blazing, 28 October 2010 - 01:14 PM.