Good spell combo for a marksman?

[dsdeiz]

Just wondering what would be a nice combo for a marksman. I was thinking of freezing an enemy first, go behind him, cast df, then use ambush and finally attacking the hell out of the enemy. Seems to be effective against locks but dunno what to do when other I encounter other classes. Archers have sotw in w/c casting time is just instant. As for warriors, I don't think I have a chance against them.. I also have sudden strike but don't really know when to cast it. Before ambush? After ambush??

Thanks!